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Lock the coupler. Even while hitched.

Cosari HitchGuard Pro

The Cosari HitchGuard Pro is a precision-machined solid brass barrel lock that slides into your coupler handle's security hole and.

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  • Works while hitched and while parked
  • Solid brass body that will not rust
  • Fits in seconds, no tools needed
  • Two nickel-plated steel keys included
Cosari HitchGuard Pro
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Small Lock. Big Difference.

Everything you need to keep your coupler shut, in a lock that fits in your palm.

Protects While Hitched

Stays in the handle on the road and at stops, so nobody can pop your coupler while you are inside paying for fuel.

Solid Machined Brass

A 95 g precision-machined brass body that shrugs off rain, road salt and mud without rusting.

Rotating Locking Cam

The offset rectangular cam turns behind the handle's security hole and holds the latch firmly closed.

Lives on Your Coupler

At 42 mm x 14 mm it is small enough to leave fitted full-time, so you never forget to bring it.

How the HitchGuard Pro Protects Your Trailer

Uses Your Coupler's Security Hole

Uses Your Coupler's Security Hole

Most latch-style couplers have a small hole in the handle. The brass barrel slides straight through it with no brackets or adapters.

One Turn Locks the Cam

One Turn Locks the Cam

Turn the key and the offset cam rotates behind the metal. The handle can no longer be lifted to release the ball.

Stays Put, Hitched or Parked

Stays Put, Hitched or Parked

Leave it on while towing and at stops. When parked, it keeps the latch closed so the trailer cannot be coupled to another hitch.

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Excellent4.8 (247)Trustpilot

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Cosari HitchGuard Pro — Solid Brass Coupler Handle Lock That Protects Your Trailer Hitched or Parked

Solid Brass Coupler Handle Lock That Protects Your Trailer Hitched or Parked

Backed by our 30-Day Money-Back Trial & Full 2-Year Cosari Warranty.

$29.99 $59.99 Free Tracked Shipping Included

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30-Day Money-Back Guarantee plus a full 2-Year Warranty.

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Description

Built for Real Towing: The HitchGuard Pro is machined from solid brass with a stepped cylindrical body and a raised ridge along the top. Brass does not rust, so it can stay on your coupler through rain, road spray and winter salt.

How It Locks: Close your coupler handle, push the barrel through the handle's factory security hole and turn the key. A rotating offset rectangular cam locks behind the metal so the handle cannot be lifted, whether the trailer is hitched or parked.

Fit Check: Look for a small round hole near the end of your coupler's latch handle. If it is there, the HitchGuard Pro will fit. If you are not sure, order with confidence under our 30-day money-back guarantee.

Shipping & 30-Day Returns

Free Shipping: Every order ships free with full tracking within 24 hours.

30-Day Trial: Try it at home for 30 days risk-free. Need help? Email us anytime at support@buycosari.com.

2-Year Warranty: If anything goes wrong within 2 years, we replace it free of charge or refund your order in full.

Why Choose the Cosari HitchGuard Pro?

Cosari HitchGuard Pro Detail

Covers the Moments That Matter

Most trailer thefts happen in minutes at fuel stops, store lots and campsites. This lock stays on when the trailer is hitched, exactly when ball-insert locks are in the cab.

You Will Actually Use It

A lock in the toolbox protects nothing. The HitchGuard Pro is small and quick enough to fit every single time.

Made to Live Outdoors

Solid brass body, nickel-plated steel keys and a smooth cylinder that kept turning after mud and rain in our tests.

Cosari HitchGuard Pro vs. Ordinary Alternatives

Cosari HitchGuard ProStandard Competitors

FeatureCosari HitchGuard ProStandard Competitors
Protects while hitchedYesNo, must be removed to hitch
Time to fitAbout 8 secondsOften 30 seconds or more
Size and storagePalm-sized, stays on the couplerBulky, carried in the cab
Rust resistanceSolid brass bodyPainted steel or cast metal that can chip
Price$29.99 (50% off today)$35 to $265

What's Included

In the Box
  • 1 × Cosari HitchGuard Pro solid brass barrel lock
  • 1 × Set of 2 nickel-plated steel keys
  • 1 × Split steel keyring
Technical Specifications
  • Material: Precision-machined solid brass body
  • Dimensions: 42 mm long x 14 mm diameter
  • Weight: 95 g
  • Locking mechanism: Rotating offset rectangular cam
  • Keys: 2 nickel-plated steel serrated keys on a split steel keyring
  • Compatibility: Couplers with a factory security hole in the latch handle
  • Use: Works with the trailer hitched or unhitched
  • Marking: Laser-engraved COSARI wordmark
Care & Safety
  • Rinse off road salt and mud with fresh water after winter or beach trips, then let the lock dry. The brass will darken to a natural patina over time, which does not affect how it works.
  • A few times a year, puff a little dry graphite lubricant into the keyway and turn the key a few times. Avoid oil or grease, which attract grit and can make the cylinder sticky.
  • Backed by our 30-Day Money-Back Guarantee & 2-Year Warranty
  • Customer Support: contact@cosarit.com
In the Box Cosari HitchGuard Pro

Fit It in Three Simple Steps

Swipe left for steps 2 and 3

  1. Close the Coupler Handle
    1

    Close the Coupler Handle

    Make sure the coupler is fully latched onto the ball, or closed if the trailer is parked, and find the security hole in the handle.

  2. Insert the Brass Barrel
    2

    Insert the Brass Barrel

    Slide the HitchGuard Pro through the security hole until the stepped body sits flush against the handle.

  3. Turn the Key and Go
    3

    Turn the Key and Go

    Turn the key to rotate the locking cam, then remove it. The handle is now locked shut.

Verified Customer Reviews

What 200+ Verified Buyers Say About the Cosari HitchGuard Pro

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4.8
Based on 247 verified reviews
5 Stars
212
4 Stars
25
3 Stars
7
2 Stars
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1 Star
1
97 % of buyers recommend the Cosari HitchGuard Pro
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✓ Verified Purchase
Alex M.1 week ago

Finally peace of mind at highway travel stops

I haul a 16-foot enclosed cargo trailer across the Midwest and always worried about somebody unhitching it while I grabbed coffee at a truck stop. This solid brass cylinder slides right into the factory aperture on my coupling handle and turns smoothly. Once that rear offset cam rotates inside, the handle cannot be lifted a millimeter whether it's on the ball or parked in my driveway. Lives in my center console when not in use.

Verified Purchase · Austin, TX · Cosari HitchGuard Pro

Customer photo
✓ Verified Purchase
Alex M.1 week ago

Heavy machined brass, zero cheap cast pot-metal

Opened the mailer box expecting something hollow for the price, but this little 42mm cylinder has real heft to it. The machining on the stepped brass body and the top ridge is super crisp, and the two nickel-plated keys turn without hanging up in the pins. Fits my boat trailer coupler like an OEM part.

Verified Purchase · Austin, TX · Cosari HitchGuard Pro

✓ Verified Purchase
Alex M.1 week ago

No exposed shackle for bolt cutters to grab

Someone cut the padlock off my landscape trailer last fall because standard long-shackle coupler locks leave half an inch of steel exposed. Because the HitchGuard Pro sits flush inside the handle recess, there is literally nothing to get jaws around. Brilliant design.

Verified Purchase · Austin, TX · Cosari HitchGuard Pro

✓ Verified Purchase
Alex M.1 week ago

Survived a coastal winter without seizing up

We keep our boat trailer near saltwater in Corpus Christi and stainless or steel padlocks usually rust shut in two months. Because the whole barrel and pin housing are solid brass, it hasn't corroded at all. Still turns like butter.

Verified Purchase · Austin, TX · Cosari HitchGuard Pro

✓ Verified Purchase
Alex M.1 week ago

Tiny enough to keep in my truck's coin tray

I used to skip locking the utility trailer on quick Home Depot runs because dragging a 12-pound wheel boot out of the truck bed was a pain. This takes three seconds to pop in and turn the key. Knocked off half a star only because I wish it came with three keys instead of two, though the blank keys are easy for a locksmith to copy.

Verified Purchase · Austin, TX · Cosari HitchGuard Pro

✓ Verified Purchase
Alex M.1 week ago

Locks both hitched and unhitched

Most ball locks only work when the trailer is disconnected. I wanted something that locks the latch down while it's actually hitched to my F-150 at hotel parking lots. Put it in, turn the key 90 degrees, and that coupling lever is completely deadlocked.

Verified Purchase · Austin, TX · Cosari HitchGuard Pro

✓ Verified Purchase
Alex M.1 week ago

Bought three for our mowing rigs

After testing one on my personal camper, I ordered three more at the 50% off price for my commercial lawn crews. The guys actually use them because there are no fussy brackets or pins to line up in the rain.

Verified Purchase · Austin, TX · Cosari HitchGuard Pro

✓ Verified Purchase
Alex M.1 week ago

Snug fit, zero rattle on bumpy backroads

Left it locked inside the coupler handle during a 400-mile trip up to Michigan. Didn't back out, didn't vibrate loose, and didn't chew up the galvanized finish on my coupler latch.

Verified Purchase · Austin, TX · Cosari HitchGuard Pro

✓ Verified Purchase
Alex M.1 week ago

Check your coupler handle slot first, works great on mine

Make sure your trailer coupling handle has the standard barrel lock hole on the side/top before ordering. Mine did, and the 14mm stepped barrel slid right into place. Very solid piece of kit.

Verified Purchase · Austin, TX · Cosari HitchGuard Pro

✓ Verified Purchase
Alex M.1 week ago

Simple, overbuilt, and effective

Sometimes the simplest engineering is the best. Just a solid 95-gram hunk of brass with a thick steel locking cam in the back. Gives me real confidence leaving my dump trailer at job sites.

Verified Purchase · Austin, TX · Cosari HitchGuard Pro

Keep Your Trailer Where You Left It

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Frequently Asked Questions

Will the Cosari HitchGuard Pro fit my trailer?

It fits couplers that have a factory security hole in the latch handle, which is common on latch-style couplers for utility, boat and small camper trailers. Look for a small round hole near the end of the handle. If you have one, the lock should fit. If not, the 30-day money-back guarantee covers you.

Can I leave the lock on while towing?

Yes. It is designed to stay in the handle while the trailer is hitched, so the coupler cannot be released at stops. Always make sure the coupler is fully latched on the ball first, and tow with your safety chains attached.

Does it work when the trailer is unhitched?

On latch-style couplers, locking the handle in the closed position keeps the jaw shut, so the coupler cannot be dropped onto someone else's hitch ball. For long-term storage of valuable trailers, we suggest adding a wheel lock as well.

Will brass rust or seize up outdoors?

Brass does not rust. It will darken to a natural patina over time, which is cosmetic. In our testing the cylinder kept turning smoothly after rain and road grime. A puff of dry graphite lubricant a few times a year keeps it that way.

How many keys come with it?

Two nickel-plated steel keys on a split steel keyring. We suggest keeping one on your vehicle keys and storing the other somewhere safe at home.

What if it does not work for me?

You have a 30-day money-back guarantee. Shipping is free and tracked, so you can follow your order to the door.

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