The standard length of a marathon is 26.2 miles, and the Britax Marathon Convertible Car Seat will cover more than 100 times that distance. The Britax Marathon Convertible car seat is one of the most functional seats to ever hit the market. Slightly larger than other Britax Car Seats, the Marathon is legendary for safety and comfort. It's important to note that the shell of the car seat is a bit bulkier than others, so parents should allow for about 31 inches of seat space when used rear facing. Some of the unique features on the Britax Marathon Convertible Car Seat include a five-point polyester harness with no-tangle polyester webbing, built in lock-offs for the car's seat belts, and a push-button LATCH system with VersaTether. This Britax Car Seat provides the utmost security in both forward and rear facing installations. The Britax Marathon has Expanded PolyStyrene (EPS) padding to protect your baby in the event of a collision. Britax convertible car seats are equipped with their patented HUGS system, which is designed to better distribute webbing loads to reduce head movement and minimize the chance for the webbing's edge to load on the child's neck. The Britax Marathon provides parents with an all around top-rated car seat. However, it might be too large for compact cars. For those looking for a smaller Britax Car Seat, the Britax Roundabout is a perfect choice. It is a little smaller than the Britax Marathon, and it is designed for children weighing up to 40 pounds.