Master Lock Fits 1-7/8" and 2" Couplers - (4) Chrome Plated Keyed Alike Trailer Locks 377KA-4 This listing is for (4) four 377KA coupler locks keyed alike and 8 keys. ATTENTION: If you order two 4-packs they will NOT necessarily be keyed the same. To ensure you get two 4-packs keyed alike, you must order the 8-pack. 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.