NIWNIW / EQUIPMENT & ESSENTIALS

Trailer Coupler & Puck Locks

Choose a trailer lock for the connection you need to secure: a compatible parked-trailer coupler, a coupler with safety-chain storage, or a door hasp. Start with the marked ball size, then match the coupler profile in the product gallery.

Coupler + chain storage · Select Bulldog / Ram profiles · Multi-size coupler lock · Compare all options ↓

XL Keyed-Alike Puck Locks — Black, 2-Pack

START WITH THE CONNECTION

The right lock. In the right place.

Shopping for a “trailer hitch lock”? First decide which connection you need to secure.

Coupler & safety chainsFor compatible parked-trailer couplers. Compare ball size, body profile and chain clearance.Compare coupler locks ↗Doors & haspsXL puck-lock packs for compatible hasps. Match the opening, locking pin and body clearance.Explore matching-key packs ↗

Receiver hitch pin locks secure an accessory inside the vehicle’s receiver; they are a different application. See the lock fit guide →

Identify your coupler from photosCompare lock sizes & applications

4 products

Which trailer lock should I choose?

Your priority Start here What determines fit
Coupler and safety-chain storage UTTC Coupler & Safety Chain Lock
Separate 2 in and 2-5/16 in configurations		 Selected size, coupler body and latch, enclosure clearance and space for the chains.
Select Bulldog or Ram couplers CTT-B 2-5/16 in Coupler Lock Exact coupler profile and surrounding hardware. The brand name alone does not confirm fit.
1-7/8, 2 or 2-5/16 in applications TTS-1 Multi-Size Coupler Lock Diagram opening: 4.37 in wide × 2.62 in high. Couplers wider than 4.37 in are not suitable; profile and latch clearance must also match.
Enclosed-trailer doors or vehicle hasps XL Keyed-Alike Puck Locks
2, 3 or 4 locks per pack		 Each hasp's dimensions, rear opening and locking-pin clearance. Keys match within the purchased pack; separate packs may differ.

Match the diagram before you order

  1. Read the coupler marking. Confirm 1-7/8 in, 2 in or 2-5/16 in on your equipment.
  2. Open the product's gallery. Compare your actual coupler with that lock's compatible and incompatible profile illustrations. Charts for different lock designs are not interchangeable.
  3. Check working space. Compare the listed dimensions and allow clearance for the latch, jack, brackets, chains and key operation.

Identify your coupler from real photos · Follow the full fit checklist

Coupler lock, hitch pin lock or puck lock?

A coupler enclosure covers a compatible unhitched, parked-trailer coupler to obstruct a new hookup. A receiver hitch pin lock secures a ball mount or accessory inside the tow vehicle's receiver. A door puck lock secures a compatible hasp. These designs protect different connections and are not interchangeable.

Locking a trailer: hitched vs. unhitched · Choosing locks for an enclosed trailer

Common questions before buying

Will any 2-5/16 in coupler lock fit?

No. Ball diameter alone does not establish compatibility. Check the exact lock's coupler chart, dimensions and latch clearance.

Is a 2-inch option suitable for a 50 mm coupler?

Do not assume so. Two inches equals 50.8 mm. Follow the marked coupler size and the exact lock instructions.

What should I look for in a heavy-duty trailer tongue lock?

Check the enclosure's fit, coverage, materials and access for normal locking and unlocking. Weight alone is not a security rating, and no lock guarantees prevention of every theft attempt.

Can I use one key for all my locks?

NIWNIW XL puck-lock keys match within the purchased pack. Matching across separate packs or with a coupler lock is not guaranteed. Compare keyed-alike pack options.

Still unsure? Ask NIWNIW about your setup with the coupler model, marked size, photos and relevant measurements. Delivery details · 30-day return conditions