The protects against trailer theft. With a 1" hardened solid steel bar, pick-resistant lock, and cut-resistant design, this coupler lock is the ultimate in trailer protection.• Universal design is compatible with all 1-7/8", 2", and 2-5/16" couplers• Locking mechanism is protected by a heavy-duty rubber cap• Comes with 2 keys Pick-resistant lock Locking mechanism is protected by a heavy-duty rubber cap Compatible with all 1-7/8", 2", and 2-5/16" couplers | BulletProof Extreme-Duty Coupler Lock