Master Lock 378DAT Coupler Lock. This coupler lock blocks the coupler from latching onto any hitch ball — making it impossible to hook up and tow your trailer away. Trailer theft is one of the most common property crimes because trailers sit unattended and a standard coupler can be hitched in seconds. This lock provides both physical security and visual deterrence — thieves look for easy targets. Master Lock construction resists cutting, prying, and picking. ⚙️ Key Features ✅ Blocks coupler from hitching ✅ Visible theft deterrent ✅ Resists cutting and prying ✅ Keyed lock, weather-resistant ✅ Master Lock quality 📐 Specifications Brand: Master Lock 🔄 Cross Reference Master Lock 378DAT | Coupler lock | Fits 2-5/16" couplers | Pin-style 🔧 Applications Coupler lock that blocks the trailer coupler from attaching to any hitch ball — the primary anti-theft device for unattended trailers. Install whenever the trailer is parked at job sites, driveways, and storage facilities. Visible bright-colored locks deter opportunistic thieves. For maximum protection, pair a coupler lock with a wheel lock or boot. Match the coupler lock to your coupler type (2" or 2-5/16" ball, lunette ring, etc.). 📞 Call/Text: 517-225-1991 🌐 AAATrailer.com
