Trimax UMAX300 Universal Dual-Purpose Trailer Coupler Lock with Integrated U-Lock

The Trimax UMAX300 is a heavy-duty, dual-purpose trailer coupler lock engineered to deliver maximum security for unattended trailers. Featuring a patented integrated U-lock system, this lock serves double duty — securing your trailer coupler while simultaneously allowing you to lock wheels, chains, or cables for layered theft protection.

Built around a 7/8" dual-locking hardened steel HEX shackle, the UMAX300 represents the top tier of the Trimax UMAX coupler lock lineup. The heavy-duty die-cast body is constructed to withstand hammer blows and harsh weather conditions, providing 360° of hardened steel protection around your coupler.

Key Features:

• Patented dual-purpose design: functions as both a coupler lock and an integrated U-lock
• 7/8" hardened steel HEX shackle for maximum cut resistance
• Universal fit — accommodates couplers from 1-7/8" to 2-5/16", including Fulton, Bulldog, Atwood, UFP, and more
• Heavy-duty die-cast body resists hammer blows and weathering
• Dual ratchet locking system for secure, rattle-free clamping
• Integrated U-lock allows secondary securing of wheels, chains, or cables
• Compatible with Trimax chains and cables for dual-force trailer security

The UMAX300 is ideal for securing boat trailers, RV trailers, utility trailers, horse trailers, cargo trailers, and powersports equipment trailers when left unattended. Pair it with a Trimax chain or cable for an additional layer of protection against tow-away theft.