Kryptonite Evolution Disck is a 14mm "horseshoe" made of hardened MAX-PERFORMANCE steel that is resistant to attempts to cut or pry it open.DOUBLE DEADBOLT locking mechanism for added security. Sliding guard protects the lock body and extends its life. Includes 3 keys - 1 key with LED with replaceable battery. Key Safe program - if keys are lost, send 1st pair of standard replacement keys free of charge. (registration required) Dimensions: 48mm x 54mm Protection level: 8/10