AeroForm Helmet Lock for Kawasaki Ninja 300/250 Lasercut from Stainless Steel - Black Powdercoated. Fits on 2013 to 2017 Model bikes. Our AeroForm Helmet Lock allows you to attach and lock the helmet to the bike. Each AeroForm Helmet Lock Kit comes with two keys. It fits nicely behind the passenger footrest holder. Installation is easy and fast.