This lock features end pin-link design secures the chain to hardened deadbolt and provides extra holding power when subjected to leverage attacks. 7mm, 4-sided chain links made of 3t manganese steel Includes 2 standard, stainless steel "I" keys High security disc-style cylinder is pick and drill resistant Key Safe Program Security Rating: 5 out of 10 Length: 85 cm (2.8 feet) Diameter: 7 mm Lock Style: Integrated Advertised Weight: 3.5lbs