Application-specific stainless steel trailer latch lock for DEMCO EZ Latch 2" ball cast couplers, using a 1/4" pin with a 2-15/16" usable span and 1-3/4" depth.
The InfiniteRule 61121-S is designed specifically for DEMCO EZ Latch 2" ball cast couplers. It helps secure the coupler latch mechanism so the latch cannot be opened or tampered with while the trailer is parked, stored, or left unattended.
This is not a general trailer door lock or compartment latch lock. It is an application-specific trailer coupler latch lock with a 1/4" diameter pin, 2-15/16" usable span, and 1-3/4" depth for the matching DEMCO EZ Latch cast coupler style.
Designed for DEMCO EZ Latch 2" ball cast couplers
Application-specific usable span for the matching coupler latch
Compact pin size for the compatible DEMCO latch lock point
Corrosion-resistant construction for towing and outdoor storage
InfiniteRule 61121-S is for the DEMCO EZ Latch 2" ball cast coupler. It should not be assumed to fit DEMCO stamped couplers, other DEMCO coupler styles, non-DEMCO trailer couplers, receiver hitches, trailer doors, gates, or storage compartments. Verify the coupler brand, coupler style, ball size, latch shape, pin hole diameter, required span, depth, and latch clearance before ordering.
Before Starting: Confirm the trailer coupler is a DEMCO EZ Latch 2" ball cast coupler and that the latch lock point accepts a 1/4" pin with a 2-15/16" span and 1-3/4" depth. Inspect the latch for damage, rust, or misalignment before installing the lock. Basic Use Steps: 1. Close the Coupler Latch: Make sure the DEMCO EZ Latch coupler is fully closed according to the coupler manufacturer’s instructions. 2. Align Lock Point: Locate the coupler latch lock opening and confirm the holes are aligned. 3. Insert Lock Pin: Slide the 1/4" lock pin through the compatible latch opening. 4. Attach Lock End: Install and secure the locking end using the included key according to InfiniteRule instructions. 5. Check Latch Security: Gently test the coupler latch to confirm it cannot open while locked. 6. Install Dust Cover: Seat the dust cover to help keep water, dirt, and grime out of the lock cylinder. 7. Store Keys Safely: Keep spare keys in a safe location and record the key number if provided. 8. Remove Before Towing if Required: Follow the trailer and lock manufacturer’s instructions before coupling and towing.
Package Contents: • 1 InfiniteRule 61121-S trailer coupler latch lock • 1/4" stainless steel lock pin with 2-15/16" span • Locking end / lock cylinder assembly • Dust cover • Keys as supplied by manufacturer or distributor packaging NOT Included — May Also Need: • DEMCO trailer coupler • Full coupler surround lock • Receiver hitch lock • Trailer door or gate lock • Compartment lock • Safety chains, towing hardware, or hitch components • Replacement coupler latch parts This listing is for the trailer coupler latch lock only unless otherwise stated. Confirm DEMCO EZ Latch cast coupler compatibility before ordering.
To confirm compatibility before ordering, have the following ready: • Trailer coupler brand and model • Whether the coupler is DEMCO EZ Latch • Whether the coupler is cast or stamped • Coupler ball size, specifically 2" for this lock • Latch lock hole diameter • Required usable span and depth • Photos of the coupler latch in the open and closed positions • Whether you need a latch lock, full coupler lock, receiver lock, or door/compartment lock Why this matters: InfiniteRule trailer latch locks are application-specific. Similar DEMCO latch styles may require different spans, depths, or lock models.
Match this lock by DEMCO coupler style, cast vs. stamped construction, ball size, pin diameter, usable span, depth, and latch clearance. Do not select it as a general trailer door or compartment lock.
If fitment or locking issues continue, check DEMCO cast/stamped coupler style, ball size, pin hole size, usable span, lock depth, latch clearance, and whether a different InfiniteRule lock model is required.
This latch lock is a theft-deterrent accessory and does not replace proper trailer coupling procedures. Always confirm the coupler is correctly latched to the hitch ball, safety chains are attached, breakaway system is connected if equipped, and all towing components are properly rated before travel. Do not tow with a damaged, mis-sized, loose, or improperly installed latch lock or coupler assembly.