Reese Towpower professional trailer coupler and towing receiver locks are the most theft resistant locks in the towing industry. Its superior strength is derived from a patented locking design that does not require shaft diameter reductions which cause weak points. Weak points enable a thief to break the lock shaft more easily and escape with your trailer. - What's Included: Two Keys - Patented design eliminates weak points - Ball bearing lock system prevents theft even if lock is broken - Bearings extend and remain in shaft inhibiting lock removal - Square key design virtually eliminates lock picking - Rubber cap keeps tumblers clean