This antitheft device combines 2-in-1 security systems: mechanical and siren alarm using motion sensor powered by 6 LR44 batteries. The alarm and batteries are independent so the lock will still work even without batteries (no siren active). Once lock pin pushed down, any attempt to break or disable the lock will trigger the siren sound for approx. 10” before automatically returning to stand-by mode. The alarm also serves as warning for owner if the lock is accidentally in place before riding.