JOHNSON - Deadbolt Blockhead Trailer Coupler Lock For 1-7/8in and 2in Couplers. Maximum security for unattended trailers. Hi-tech materials redefine the traditional lip engaging coupler lock. Extruded, tempered aluminum body provides superior strength to weight ratio, a distinctive look, and great value. Simple, rugged push button lock mechanism. Double-sided automotive style key makes for easy insertion and removal. Shuttered key opening prevents clogging and freezing. Durable powdercoat finish. Fits all flat lip 1-7/8in and 2in couplers. Fits all 1-7/8in and 2in lip-engaging, trigger style couplers. Coupler should have rolled lip around the bottom. Maximum lip width: 3-3/4in. 5-pin tumbler 2 keys. Material: extruded tempered aluminum body. Finish: powdercoat. Made in USA.