The Mastiff DB Chain Lock by OnGuard is a compact and sturdy security solution for your bicycle. The lock features an 8mm titanium reinforced hardened steel square link chain, providing exceptional strength and durability. The Mastiff rotary lock utilizes a Deadbolt mechanism, offering added security and resistance against break-ins. The lock also features an armor-protected hardened steel shackle, providing extra protection against cuts. The heavy-duty stainless steel body, along with an inner base, further enhances security. The rotary style lock ensures smooth and easy operation with just one hand. The tight shackle-to-body clearance eliminates pry points, making it difficult for thieves to cut through. The lock comes with 5 heavy-duty F-style keys, offering convenience and peace of mind. With its 80x8mm (WxH) chain dimensions, this chain lock is a reliable and secure option for your bike.