In Compliance with SFI Spec 20.1 and WKA and IKF standards. One of the most important things you can buy to Protect Your Child! Sizes: comes in 1 size that fits ages 5-12 Our K1 Go Kart Chest Protector has been rigorously tested and designed for maximum protection and comfort. Lightweight made with two layers of vacuum formed polypropylene plastic and strong, heavy duty buckles. Perfect for all types of youth Karting.