The gel liner has been designed to take a self-fit custom impression of your teeth upon purchase to ensure security and comfort throughout the guards lifespan; With your teeth nestled in the vertical wall frame, the jaw line is secured limiting injury from side impact; Take the personalization of your Shock Doctor product even further by choosing from an array of offered colors; Features High impact shock absorption; Increased athletic performance"> Tough protective outside, soft comfortable inside. Dual density semi-rigid exoskeletal frame, rear molar cushions and solid outer shell with wall extensions help reduce jaw injuries caused by front and side impacts. Soft gel fit material molds to teeth for a tight comfortable fit. Convertible quick release tether allows mouth guard to be strapped or strapless.