Giro Discord Helmet, Adult Size, Medium (55.5-59cm), Matte Dark Shadow Soft Shell interior Construction Dual Density Vinyl Nitrile (VN) Liner Auto Loc 2 Fit System On-The-Fly Vertical Tuning Super Cool Vents with Thermostat Control Stack Ventilation Removable Goggle Retainer Certification: CE EN1077 Giro Discord helmet has an adjustable fit system, able to loosen up in order to create a little more room. The system is quite simple, with two plastic tabs on either side that click into and adjust to different points along the inside of the helmet. The back of the fit system is also made of an elastic strap that can adds a little more stretch. Used maybe 3 times over one season. No high energy impacts. Some slight scuffs on exterior.