Start with the part you need to secure: the ball socket on a disconnected trailer or the closed coupler latch. Then check the product's dimension drawing against your coupler. Ball size alone does not confirm that a lock will fit.
| Lock style | Check before ordering | Compare options |
|---|---|---|
| Coupler-body lock | Marked ball size, coupler shape, lip clearance and space to position the lock. | 2-5/16-inch round lock or 2-5/16-inch hexagon lock |
| Adjustable coupler lock | Listed coupler sizes and whether the locking position seats correctly around your coupler. | RTL002 adjustable coupler lock |
| Combination latch lock | Closed-latch width, locking-hole size and room to reach the dials. TL200-RT-C-K has a maximum locking span of 1.1 inches. | 4-digit combination latch lock |
Use the coupler lock measurement guide to record your dimensions. For a keyless latch lock, follow the combination lock fitment checklist. Compare the body, pin or shackle, cylinder and finish in the trailer lock materials guide.
Choose a lock you can fit and operate consistently. No lock guarantees theft prevention; combine suitable locks with secure parking and storage practices. See the trailer parking and storage checklist, or contact RETRUE for lock fitment help.
Stop theft before it starts and protect your investment with RETRUE’s heavy-duty trailer locks. Engineered with tamper-proof steel and weather-resistant coatings, our locks provide the ultimate towing security for RVs, boat trailers, and campers.
