The GLX 316 is specially designed for all kids out there that need a full face helmet. There is focus on maximum protection for every type of rider out there whether it be a parent who wants their kid to have the proper protection or the youth enthusiast that rides any type of motorcyle or recreational vehicle. There are 5 different color options and sizes available from S-L. For proper fit and size measure the circumference of your head 1" above your eyebrows and around the largest portion of the back of your head. 19 1/4" - 19 3/4" = Small; 20" - 20 1/2" = Medium; 20 7/8" - 21 1/4" = Large.