The OnGuard Mastiff 4.2 ft Chain with X4 Padlock delivers strong, versatile protection with a heavy-duty titanium-reinforced hardened steel chain and compact Boxer padlock. The 130 cm (4.22 ft) chain features rugged 10 mm hexagonal links engineered to resist cutting, prying, and leverage attacks in urban environments. Its unique cinch-loop design allows riders to maximize locking efficiency by tightening the chain around racks, poles, or bike frames for a more secure setup. The included Boxer U-lock padlock uses the X4P Quad Lock mechanism to secure the shackle on four sides, eliminating weak points and resisting twisting or pulling attacks. An advanced Z-Cylinder core provides added defense against picking, drilling, and bumping attempts. Durable protective coatings help prevent scratches on frames and finishes, while the included key set ensures convenient daily use. Includes five laser-cut keys.