14mm six-sided chain links made of 3t HARDENED MANGANESE STEEL for ultimate strength. Durable, protective nylon cover with hook-n-loop fasteners to hold in place. Includes maximum security New York Disc Lock with 15mm MAX-PERFORMANCE STEEL SHACKLE. Patented*, oval hardened STEEL CROSSBAR for extra security. Hardened DOUBLE DEADBOLT locking for extensive holding power. HIGH SECURITY DISC-STYLE CYLINDER with reinforced anti-drill, anti-pull protection system. SLIDING DUSTCOVER protects and extends cylinder life. 3 STAINLESS STEEL KEYS â€“ one lighted with high intensity bulb and replaceable battery. Key Safe Program.Product dimensions: 3.25â€™ (100cm) chain length, 15mm shackle diameter.