Master Coupler Lock - Universal Trailer Locks #379KA-2 Two (2) high quality trailer coupler (tongue) locks keyed alike, same key opens all. Each lock weighs 2.4 lbs. Fits virtually all 1-7/8, 2", and 2-5/16" couplers. Advanced locking mechanism resists picking and prying and is rekeyable - for rekeying see your authorized Master Lock locksmith. Limited Lifetime Warranty. Resists rust and corrosion. Simple installation and removal.