Black keyed trailer hitch coupler lock with a steel pin and two silver keys on a white background
Trailer Security

Trailer Hitch Coupler Lock (Keyed)

5.0 · 5 reviews

The latch stays locked, so the trailer stays where you parked it.

$24.99One-time · free tracked shipping
Free tracked shipping Free 30-day returns 1-year warranty
  • Locks the coupler latchThe 1/4 in pin passes through the latch on a ball-hitch coupler and locks there. With the latch blocked, the trailer can’t be dropped onto someone else’s ball.
  • Zinc alloy, anti-pick keywayThe body is zinc alloy and the keyway is anti-pick, so the lock itself isn’t the easy part to get past.
  • Two keys in the boxOne key rides on your key ring. Keep the second at home, so a lost key never leaves the trailer locked to nothing.
  • Nothing to installNo drilling, no bolts, no tools. It goes on when you unhitch and comes off when you hitch up again.
Trailer Hitch Coupler Lock (Keyed) $24.99

Why lock the coupler

A trailer is the one thing you own that’s built to leave with a stranger.

Most of what we lock up is hard to move. A trailer is the opposite. It sits on its own wheels with a coupler on the front that is designed to drop onto any ball and roll. That’s what makes it useful on a Saturday, and it’s what makes it easy to take on a Tuesday night while it waits in the driveway or the storage lot.

Nobody has to break anything. The coupler latch is the whole connection between a trailer and whatever truck is in front of it. If the latch can close on a ball, the trailer can go. If it can’t, the trailer stays a heavy object on wheels that someone has to deal with in plain view.

A coupler lock takes the latch out of play. The pin goes through it, the lock closes, and the one quick way to hitch up is gone. It’s a small piece of hardware for a gap that’s easy to miss, because the trailer looks parked and safe. The habit is the only part that takes effort: lock it every time you unhitch, including the short stops.

If the latch can’t close on a ball, the trailer can’t roll away on one.
1/4in
pin through the coupler latch
2keys
included in the box
0tools
to put it on or take it off
30days
to send it back
Black keyed coupler lock fitted on the ball-hitch coupler of a galvanized utility trailer on a gravel driveway
Driveway or storage lot

Same lock at home and wherever the trailer waits.

At home, the trailer sits where you can see it from the kitchen, most of the time. The lock covers the hours you can’t: overnight, the weekend you’re away, the afternoon everyone is out. Unhitch, pin through the latch, lock, and the coupler is out of play until you come back with the key.

At a storage lot, the trailer sits among dozens of others for weeks. A locked coupler there does the same job without you around. It’s one more thing standing between a stranger’s truck and your trailer, and it’s visible to anyone who walks up to the hitch.

Locks the latch1/4 in pinZinc alloy body2 keys included
Setup

Setup is part of unhitching

1

Check your coupler

Before the first use, look at the latch on your ball-hitch coupler and check it has a hole a 1/4 in pin can pass through.

2

Unhitch as usual

Lift the coupler off the ball and set the trailer down the way you always do.

3

Pin through the latch

Push the pin through the hole in the coupler latch and close the lock body over it.

4

Lock it and store the spare

Turn the key, pull on the lock to check it’s closed, and keep the second key somewhere other than the truck.

Lock it every time the trailer is unhitched, including short stops. It works only while it’s on the latch.
Where it belongs

Any trailer that spends nights unhitched

An RV in the side yard, a boat trailer at the storage lot, a utility trailer behind the garage: if it sits unhitched with a ball-hitch coupler, this is the cheapest way to take the quick hitch-and-go off the table. It’s $24.99, there’s nothing to install, and you can check the fit by looking at your own latch. If it doesn’t fit or doesn’t do what you just read, send it back inside 30 days. Shipping to the US, Canada, the UK, Australia and New Zealand is free, and most orders arrive 1 to 3 weeks after ordering.

Layer your defense

The lock covers the trailer. The alarm covers the garage.

The coupler lock keeps the trailer from being hitched, but it can’t tell you when someone is working the garage or shed door where the tow gear and tools live. A TremShield Alarm is a thin stick-on alarm for that door or its window, no Wi-Fi and no subscription, and it fires a 125dB siren the moment it’s forced. One alarm is $29.99; six are $99, which is $16.50 per alarm (Save $80.94).

See the alarm
White TremShield vibration sensor alarm
Good to know

Questions, answered calmly

It’s made for ball-hitch couplers on RV, boat and utility trailers, and it uses a 1/4 in pin. To check yours, look at the coupler latch: it needs a hole a 1/4 in pin can pass through. If it doesn’t fit, you can send it back within 30 days.

A coupler lock puts a pin through the latch on the trailer’s coupler and locks it there. With the latch blocked, the coupler can’t be closed onto a ball, so the trailer can’t be hitched to someone else’s truck and towed away.

It locks the coupler, not the wheels, and it doesn’t make the trailer impossible to steal. It stops the quick hitch-and-go. Someone with cutting tools and time is a different problem, which is why it works best as one layer alongside a locked garage or a well-lit spot.

The trailer hitch coupler lock, with its 1/4 in pin and zinc alloy body, and 2 keys. There is nothing else to mount or install.

It goes on as part of unhitching. Lift the coupler off the ball, push the pin through the latch, close the lock and turn the key. No drilling and no tools. Lock it every time the trailer is unhitched, because it only works while it’s on.

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