Master Lock Co 389DAT Universal Trailer Coupler Lock

Product Description

The MASTER LOCK CO 389DAT is a universal trailer coupler lock designed to secure trailer couplings against unauthorized tow-away theft. It fits the three most common coupler ball sizes: 1-7/8 inches (48 mm), 2 inches (51 mm), and 2-5/16 inches (59 mm), making it a versatile single-unit solution for mixed fleets or job-site trailers. The advanced internal locking mechanism is engineered to resist picking and prying, two of the most common bypass methods. The unit is finished to resist rust and corrosion, supporting long-term outdoor exposure. Installs and removes without tools, which suits frequent use by contractors, fleet managers, and equipment rental operations.

This coupler lock is suited for light-duty to medium-duty trailers including utility trailers, landscaping trailers, equipment haulers, and recreational trailers. Because it spans the three standard coupler sizes, a single 389DAT can serve multiple trailers on a job site without needing a separate lock for each hitch configuration. The package contains two units, making it practical to secure more than one trailer at a time or to keep a spare on hand.

Key Features

• Fits 1-7/8 inch, 2 inch, and 2-5/16 inch ball couplers in one universal design
• Advanced locking mechanism resists picking and prying
• Guards against trailer tow-away theft
• Rust- and corrosion-resistant finish for outdoor durability
• Tool-free installation and removal for fast deployment
• Sold as a package of 2 units

Compatibility

Designed to fit most standard trailer couplers sized 1-7/8 inches, 2 inches, and 2-5/16 inches. Suitable for utility, equipment, and recreational trailer applications using these common coupler ball sizes.

Installation Notes

Installation is performed by aligning the lock body over the open coupler jaw and engaging the locking mechanism by hand. No special tools are required. Before installing, confirm the trailer is on a level surface and the coupler latch is in the open position. Verify the lock is fully seated and the mechanism is engaged before leaving the trailer unattended.

Technical Specifications

• Compatible Coupler Sizes: 1-7/8 inches (48 mm), 2 inches (51 mm), 2-5/16 inches (59 mm)
• Weight: 6.4 pounds
• Package Quantity: 2 units per package
• Unit of Measure: EA

Standard Information

• Brand: MASTER LOCK CO
• Manufacturer Part Number: 389DAT