Master Lock Fits 1-7/8" and 2" Couplers - (3) Chrome Plated Keyed Alike Trailer Locks 377KA-3 This listing is for (3) three 377KA coupler locks keyed alike and 6 keys. If you order two 3-packs or any multiple of this lock we will automatically key them all the same. SPECIFICATIONS: Fits 1-7/8", 2" and some 2-5/16" trailer couplers. For 2-5/16" couplers we recommend a different lock, search Master Lock 379KA. DURABLE DESIGN: Chrome finish resists rust and corrosion. Advanced locking mechanism resists picking and prying. Easy to install and remove. Limited Lifetime Warranty provides peace of mind from a brand you can trust.