Performance & Use Case
The Onguard Mastiff Chain Lock delivers Sold Secure Gold-rated protection - one of the highest UK lock standards - with the flexibility of a chain-plus-U-lock format. The Boxer U-lock can also be used independently as a disc lock, providing two security tools in one purchase.

Construction & Security
The 10mm hexagonal-link chain is reinforced with titanium and made from hardened steel for high cutting and prying resistance. The chain cover protects paintwork and carries an embroidered logo that won't flake or wear off. The Boxer U-lock features the X4P Quattro Bolt mechanism for four-sided shackle locking, with the Z-Cylinder providing bump, pick and drill resistance. A 14mm hardened steel shackle resists cutting, prying and jacking. Co-moulded crossbar cover and double rubber-coated shackle protect finishes.

Length & Format
Available in two chain lengths: 110cm and 180cm. The 110cm secures bike to rack with the U-lock used as the closing piece; the 180cm gives reach to lock through wheels or to multiple bikes. Each variant includes 5 laser-cut keys with one LED micro-light, an embroidered chain cover, and a lifetime warranty.