Kryptonite Evolution Mini-6 pin lock with key locking mechanism.11 mm hardened steel horseshoe Disc lock provides a high level of security Transit Flex Frame-U system for attaching to the bike frame Vinyl finish, No scratches on bike frame 3 keys supplied with lock (including 1 with backlight) Key Safe program (new key can be ordered) Dust and moisture protection Shock and noise protection Level of protection 7 out of 10 Diameter 11 mm Dimensions: 7 x 15.2 cm