--- product_id: 2022307 title: "Britax Marathon 70 Convertible Car Seat (Previous Version), Onyx (Prior Model)" brand: "britax" price: "€ 154.46" currency: EUR in_stock: false reviews_count: 4 url: https://www.desertcart.it/products/2022307-britax-marathon-70-convertible-car-seat-previous-version-onyx-prior store_origin: IT region: Italy --- # Quick adjust harness 5-70 lbs capacity Side impact protection Britax Marathon 70 Convertible Car Seat (Previous Version), Onyx (Prior Model) **Brand:** britax **Price:** € 154.46 **Availability:** ❌ Out of Stock ## Summary > 🚗 Safety Meets Style: The Ultimate Car Seat for Your Precious Cargo! ## Quick Answers - **What is this?** Britax Marathon 70 Convertible Car Seat (Previous Version), Onyx (Prior Model) by britax - **How much does it cost?** € 154.46 with free shipping - **Is it available?** Currently out of stock - **Where can I buy it?** [www.desertcart.it](https://www.desertcart.it/products/2022307-britax-marathon-70-convertible-car-seat-previous-version-onyx-prior) ## Best For - britax enthusiasts ## Why This Product - Trusted britax brand quality - Free international shipping included - Worldwide delivery with tracking - 15-day hassle-free returns ## Key Features - • **Built to Last:** Integrated steel bars enhance stability and reduce flexing in the event of an accident. - • **Versatile Use:** Designed for children from 5 to 70 pounds, ensuring safety through all growth stages. - • **Cocoon of Comfort:** Deep side walls with energy-absorbing foam provide ultimate protection for your little one. - • **Safety First, Always!:** Equipped with Safecell technology to lower the center of gravity during a crash. - • **Effortless Adjustments:** Quick adjust harness allows for easy height changes without the hassle of re-threading. ## Overview The Britax Marathon 70 Convertible Car Seat is a top-tier safety seat designed for children weighing between 5 to 70 pounds. It features advanced Safecell technology, integrated steel bars, and side impact protection, ensuring your child's safety and comfort during every ride. With a quick adjust harness and a versatile design, this car seat grows with your child, making it a smart investment for modern parents. ## Description .com The BRITAX MARATHON 70 Convertible Car Seat achieves optimum head safety through the combination of BRITAX SafeCell Technology, integrated steel bars, and a Versa-Tether, which work together to minimize head excursion and reduce the risk of head injury during a frontal impact. It also features easy installation, Side Impact Protection, and innovative details for your child's comfort and safety. The seat fits children in the rear-facing position weighing from 5 to 40 pounds, and children in the forward-facing position starting at one year old and 20 pounds, up to 70 pounds. MARATHON 70 (Onyx)Convertible Car SeatAt a Glance:Age/Weight Requirements: In rear-facing position, fits children weighing 5 - 40 pounds; in forward-facing position, fits children 1+ years old weighing 20 - 70 poundsWarranty: 1-yearlimited warrantyAvailable in (from left to right): Onyx, Crimson, Waverly,Cowmooflage, Blueprint, and Allison.Safety features include SafeCell Technology and True Side Impact Protection. View larger.Comfort features include dual recline positions and high-density comfort foam.(Shown here in Allison.) View larger.BRITAX 360 Degree ProtectionThe BRITAX MARATHON 70 features technologies that work to minimize injury to your child during a crash from any direction, including both frontal and side impact crashes - the most frequent types of crashes. These technologies work together with other features on the car seat to minimize injury to your child during a crash by: keeping your child in the vehicle,diverting crash forces away from your child,helping to slow down your child's body,minimizing movement of your child, andprotecting your child's brain and spinal cord.SafeCell Technology for Advanced Head Safety Designed with SafeCell Technology, the MARATHON 70 features SafeCells, which are engineered structures located in the base of the seat designed to compress in the event of a crash. This compression significantly lowers the center of gravity and counteracts the forward rotation of the car seat, delivering unprecedented performance in a crash.The MARATHON 70 also features integrated steel bars, which strengthen the connection to the vehicle seat and reduce the forward flexing of the car seat. In addition, the energy-absorbing Versa-Tether anchors the top of the car seat and minimizes forward rotation of the car seat to reduce the crash forces that can reach your child if an accident occurs. These three features work together as a system to provide revolutionary head safety protection for your child.Side Impact Protection for Added SecurityTo keep your child safe in the event of a side-impact collision, the MARATHON 70 includes Side Impact Protection. Side Impact Protection is a system composed of a rigid seat shell with deep side walls and energy-absorbing EPP (Expanded Polypropylene) foam lining the seat shell. These combined features work together to protect your child's head and chest from incoming crash forces by distributing the forces over a larger surface area, helping shield your child from vehicle intrusion and contain your child's head and body in the seat.Premium Fit and Comfort FeaturesWhether children are watching the world go by or snuggling in for a nap, they'll enjoy that the MARATHON 70 reclines in both the forward and rear positions. And thanks to additional features, which include high-density comfort foam and a plush cover set with a matching belly pad, they'll always ride in style and comfort. A 70-pound weight capacity, two buckle positions, and a tangle-free five-point harness with ten harness-height settings provide a snug, custom fit for your growing child. Plus, an optional Infant Positioning Insert (sold separately) allows you to properly and snugly fit smaller infants into the car seat.Ease-of-Use for Safety and Convenience Packed with perks for parents, the MARATHON 70 makes it easy to secure your child in the proper position without guesswork. Premium lower LATCH connectors make for a quick, simple, and tight installation, while the push-button allows you to easily uninstall the connectors. Easy-to-access built-in lock-offs allow you to install the car seat with ease using your vehicle's lap and shoulder belt. The quick-adjust harness system and buckle allow you to reposition the harness height without disassembling the harness straps.Additionally, an anti-slip contoured base grips and protects the vehicle seat, ensuring a tight installation in all types of vehicles. Convenient holders keep harness straps out of the way when you're placing your child in the seat, and the plush cover set with matching pads removes easily for cleaning without requiring you to disassemble or uninstall the car seat.The BRITAX MARATHON 70 Convertible Car Seat is backed by a one-year limited warranty.What's in the BoxOne BRITAX MARATHON 70 Convertible Car Seat and manual. From the Manufacturer The Britax Marathon 70 convertible car seat is designed for children rear facing from 5 to 40 pounds and forward facing up to 70 pounds. The Marathon 70 achieves revolutionary head safety through the use of patent-pending Britax SafeCell Technology, integrated steel bars, and versa-tether that work together to minimize head excursion and reduce the risk of head injury during a frontal impact. The Marathon 70 also incorporates Britax Side Impact Protection, offers a no-rethread, five-point harness, a quick-adjust head restraint, multiple buckle and recline adjustments, and an easy access cover and access to belt paths from the front of the seat. A head and body pillow is provided for comfort and infant positioning. ## Features - The Britax Marathon 70 convertible car seat is designed for children rear facing from 5 to 40 pounds and forward facing up to 70 pounds - Safecell technology features safecells designed to compress in a crash, significantly lowering the center of gravity and counteracting the forward rotation of the child seat which normally propels child toward the front seat - Integrated Steel Bars strengthen the connection to the vehicle and reduce forward flexing of the child seat during a crash - Side Impact Protection comprised of deep side walls lined with energy absorbing EPP foam distributes crash forces, shields from vehicle intrusion and contains the head, neck and body - Quick adjust harness reposition the harness shoulder height without disassembling the harness straps ## Technical Specifications | Specification | Value | |---------------|-------| | Product Dimensions | 19.5 x 18.5 x 26 inches | | Item model number | E9LB11A | | Is Discontinued By Manufacturer | No | | Minimum weight recommendation | 5 Pounds | | Maximum weight recommendation | 70 Pounds | | Material Type | Alloy Steel | | Additional product features | Adjustable Head Support | | Number Of Items | 1 | | Orientation | Rear Facing | | Rear-facing minimum child weight | 5 Pounds | | Forward-facing maximum child weight | 70 Pounds | | Item Weight | 19.5 pounds | ## Product Details - **Brand:** BRITAX - **Installation Type:** Latch - **Material:** Alloy Steel - **Color:** - Onyx - **Orientation:** Rear Facing ## Images ![Britax Marathon 70 Convertible Car Seat (Previous Version), Onyx (Prior Model) - Image 1](https://m.media-amazon.com/images/I/81mnOGRVH2L.jpg) ## Customer Reviews ### ⭐⭐⭐⭐⭐ Installed in 2009 Accord *by C***Y on July 31, 2011* My husband and I researched carseats for a while before deciding on the Britax Marathon 70. We needed 2 carseats. We bought this one for my 2009 Honda Accord and a First Years True Fit for my husbands Jeep Wrangler. My 1 year old daughter is in my car more often so we wanted to splurge on one of the carseats. I'm so glad we did.After taking the time to read the instruction manual, the actual installation was pretty easy. (Not so easy with the True Fit in my husband's Jeep, but that's for another review) We installed it rear facing using the Latch system. I was not able to use the Latch with our infant seat because in using the middle of the back seat the Latch was too far apart. With the Britax Marathon 70, it states you can use the Latch up to 20 inches apart. Mine were about 16 inches. I did have to roll up a towel in order to get the seat level. I wish it had a better way of determining it being level. You just have to gauge it by determining whether a line on a sticker is parallel to the ground. I would feel more comfortable not just "eye-balling" it.The Marathon 70 has velcro on the straps to stick them to the seat to aid in getting her your child in the carseat without having to dig under him/her for the straps. This also helps with the straps not getting twisted. I wasn't sure about the bellypad at first. I liked the idea of it, but it seemed to flop down, and I had to dig it out under my child. Now after using it a week, I'm getting the hang of it. I am able to fold it forward before putting my daughter in and it stays forward. I also like how you can adjust the height and tightness of the straps without taking the seat out of the car. It is very easy to use.I was worried about it fitting in my Honda Accord. We installed it rear-facing in the middle of the backseat, and it fits perfectly. I have a mirror attached to the back headrest and I can check on my daughter using the rearview mirror. She seems very happy and comfortable so far in her seat.I am very pleased with my purchase and feel like this seat is worth the money. ### ⭐ DO NOT BUY - CAUSES BACK PAIN IN TODDLERS!!! *by J***A on August 23, 2012* I bought this car seat in December 2010. My son turned two in February, and in March, he began complaining of back pain. We've taken him to his pediatrician and we've had multiple tests including a back x-ray performed on him to try to determine the source of the pain. Interestingly, we found this thread when searching for back pain in toddlers:[...]It is amazing how many of these people own Britax car seats, have toddlers that complain of back pain, and have that back pain magically disappear when they switch to another seat. So, we just switched to the Graco Nautilus seat, and today my son says, "seat no hurt back daddy!".We called Britax, and they are completely insensitive to the issue. They told us that there is nothing they can do and that they have never gotten a single complaint about back pain with their seats. Unbelievable when you look at the link above. BOTTOM LINE: SAVE YOUR CHILD'S BACK. DO NOT PURCHASE THIS SEAT! ### ⭐⭐⭐⭐ does the job *by B***E on October 17, 2011* This car seat is nice and like everyone else, I too appreciate that my baby can stay in it for so long. The cover is fairly easy to remove for washing. I like that there a few different pieces so that if only one part is dirty, I don't have to take the entire cover off. There are a couple of things that I don't like about this seat and that is why I gave 4 stars. 1 I don't like the velcro on the waist belt and side cover. It doesn't do what it is meant to do and I just don't like something so scratchy being near my baby. 2 I feel like the head area is so wide and if my baby falls asleep in the car (which nearly all babies are prone to do), his head falls to his shoulder. I know babies are like rubber but I personally don't like sleeping that way (on a plane) so I don't want my baby to be uncomfortable. Also, if he is asleep and I need to turn a corner, his head goes from one side to the other. I just don't like all of the jostling around. Plus, I feel that if I were to ever get into an accident, his poor little head would get knocked around a lot because the area is so wide. To fix this, I put folded up receiving blankets between the headrest and the seat so that the head bumper is closer to his head and he can basically keep his head upright even while he sleeps. As a tip, if you will ever be taking this car seat in and out of a vehicle, I recommend safety pinning the pocket in the back that stores the access belt. The pocket does not close and the belt is so long that having it fall out is a pain. After two nightmare-ish events at the airport and again trying to get on a cruise ship, I learned my lesson. --- ## Why Shop on Desertcart? - 🛒 **Trusted by 1.3+ Million Shoppers** — Serving international shoppers since 2016 - 🌍 **Shop Globally** — Access 737+ million products across 21 categories - 💰 **No Hidden Fees** — All customs, duties, and taxes included in the price - 🔄 **15-Day Free Returns** — Hassle-free returns (30 days for PRO members) - 🔒 **Secure Payments** — Trusted payment options with buyer protection - ⭐ **TrustPilot Rated 4.5/5** — Based on 8,000+ happy customer reviews **Shop now:** [https://www.desertcart.it/products/2022307-britax-marathon-70-convertible-car-seat-previous-version-onyx-prior](https://www.desertcart.it/products/2022307-britax-marathon-70-convertible-car-seat-previous-version-onyx-prior) --- *Product available on Desertcart Italy* *Store origin: IT* *Last updated: 2026-05-15*