Size Name:M (57) Shoei GT-Air II Insignia TC-5 Helmet The Shoei GT-AIR II follows the successful footsteps of its predecessor. The Japanese helmet experts have really pulled all the registers to give you a particularly comfortable motorcycle helmet. With three outer shell sizes, the forward-facing ratchet buckle, an optimised ventilation system and the larger sun visor – everything is designed to give you more driving fun under all conditions.