Universal Helmet Lock - Mono - Lasercut from Stainless Steel - Black Powdercoated. Our Universal Helmet Lock - Mono - allows you to attach and lock one helmet to the bike. Each Mono Helmet Lock Kit comes with two keys. It fits nicely behind the license plate, the design is reversible and can be configured as left or right sided lock. The mounting holes are 99 mm apart and have 35 mm slots. Installation is easy and fast.