On Guard Bulldog Series U-Locks X2 Power Double Bolt Locking Mechanism locks shackle on both sides M-Cylinder resists all attacks from picking, pulling or drilling Popular 115mm x 230mm (4.53 x 9.06) shackle length Hefty 13mm (0.51) hardened steel shackle resists cutting, prying and jacking Rounded design and centered keyway eliminates pry points. 5 Laser Cut Keys, 1 with a LED micro-light.