10mm six-sided chain links made from 3T MANGANESE STEEL. Patent-pending END LINK DESIGN secures chain to hardened deadbolt eliminating critical vulnerability. HIGH SECURITY DISC-STYLE CYLINDER is pick and drill resistant. Patented, reinforced OVAL CROSSBAR LOCK HEAD. SLIDING DUSTCOVER protects and extends cylinder life. 3 STAINLESS STEEL KEYS – one LED lighted key with replaceable battery and 2 new, ergonomic ‘I” keys. Durable WEATHER-RESISTANT nylon sleeve prevents scratches. Key Safe Program. Product dimensions: 5.25' (160cm) chain length.Product weight: 9.70 lbs (4.40 kgs).