The 3M Versaflo M-930 Visor lock kit is an accessory to 3M Versaflo M-400 Series Helmets. The lock mechanically attaches the visor frame to the jaw of M-400 series helmets with the intent to prevent lifting of the visor if needed or preferred by users. The lock is sold as a retrofit kit with 5 locks, and can be installed on new or existing helmets. Helmet purchased separately.