The OnGuard RockSolid U-Lock is engineered for riders who demand maximum protection against modern theft tools. Featuring a proprietary angle-grinder-resistant coating combined with a 14 mm tri-radius hardened steel shackle, this lock is built to withstand saws, cutting wheels, leverage bars, and twisting attacks commonly used by thieves. Its X4P Quad Locking Mechanism secures the shackle on all four sides to prevent spreading or rotation under force. Despite its extreme strength, it remains portable at only 3 lbs and includes OnGuard’s industry-leading anti-theft coverage for bicycles and powersport equipment. Ideal for high-risk urban areas, e-bikes, cargo bikes, and daily commuters who require advanced security.