OnGuard Brute LS U-Lock (16mm) BRUTE SERIES | Ultimate protection for high crime areas. X4P Quattro Locking Mechanism for four-sided protection. Massive 16.8 mm (0.66") hardened steel TriRadius shackle resists all forms of cutting, prying or jacking and provides extra room for more locking options. New crossbar and shackle coatings protect finishes. X4P Quattro Bolt Locking Mechanism locks shackle on four sides.