Our best selling u locks featuring best in class x2p double bolt lock mechanisms and super strong 13mm hardened steel shackles for a full circle of protection. X2p double bolt locking mechanism locks shackle on both sides z cylinder is bump proof and resists picking pulling or drilling hefty 13mm hardened steel shackle resists cutting prying and jacking rounded design and centred keyway eliminates pry points double rubber coated crossbar cover protects paint and finishes extra thick moulded end caps protects against bumps and hits locking mechanism x2p double bolt tumbler mechanism z cylinder european type shackle diameter 13mm hardened steel coatings double rubber coated crossbar with extra thick end caps fully rubber coated shackle keys 5 laser cut keys 1 with led microlight warranty lifetime extras all tube mounting bracket included