ONGUARD Bulldog Medium Mini Lock X2 Power Double Bolt Locking Mechanism locks shackle on both sides M-Cylinder resists all attacks from picking, pulling or drilling Medium length 175mm (6.90) shackle still fits around new standard parking meter post 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.