5mm, four sided chain links made from hardened carbon steelHardened locking pin provides additional holding powerWafer style cylinder offers resistance from picking and drillingDurable weather resistant nylon sleeve prevents scratchesIncludes 2 new ergonomic keysKey safe program replaces lost keys (after registering through kryptonite)5mm2`8`/81.25cmKeyBlack4 of 10UPC/EAN/GTIN: 720018004912