This carabineer-style universal helmet lock protects your helmet, jacket or bag from casual grab-and go theft. The lock is small enough to fit into your pocket, but big enough to fit around most any handlebar or engine guard (1.5"/38mm max). No keys are required. Simply set your own 4-digit code, slip the carabineer through your helmet D-ring, and close the outward-opening lock. The aluminum and zinc alloy carabineer is covered with a tough rubber coating to protect the surrounding finishes.