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Master Lock Coupler Lock (Model 2847DAT)
  • MaterialHardened steel
  • Compatible Coupler…1-7/8 in., 2 in., 2-5/16 in.
  • Weight2.9 lbs

Safety & Locks#3 of 8 in Safety & Locks

by Master Lock

Master Lock Coupler Lock (Model 2847DAT)

The Master Lock Coupler Lock is a dependable, affordable security upgrade for RV and camper owners looking to deter trailer theft at campgrounds, storage lots, or driveways.

4.4
HitchHaven score4.4 out of 5 · our editorial rating
  • Solid steel construction with hardened finish
  • Fits most 1-7/8 in., 2 in., and 2-5/16 in. couplers
  • Adjustable span to accommodate different coupler sizes
  • Weather-resistant protective housing covers keyway
  • Includes two keys with serialized spare key tag
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OverviewSpecsPros & consFull reviewRelated

The verdict

The Master Lock Coupler Lock is a dependable, affordable security upgrade for RV and camper owners looking to deter trailer theft at campgrounds, storage lots, or driveways. Its rugged steel build and weatherproof design make it a solid long-term investment, though users in cold climates should apply graphite lubricant periodically to keep the keyway smooth.

Spec plate

Material
Hardened steel
Compatible Coupler Sizes
1-7/8 in., 2 in., 2-5/16 in.
Weight
2.9 lbs
Keys Included
2 keys with spare key tag
Lock Type
Keyed coupler lock

Pros & cons

What we like

  • Deters trailer and coupler theft effectively
  • Durable all-weather steel build resists cutting and prying
  • Quick and simple installation without tools
  • Compact design doesn't interfere with towing hardware
  • Keyway cover protects lock from dirt, ice, and rust

What to watch

  • Key cylinder can stiffen in freezing temperatures without lubrication
  • Slightly heavy to carry for frequent hitch-up/down use
  • Limited to ball-style couplers, won't fit all pintle hitches
  • Paint/finish may chip with heavy long-term outdoor exposure

Full review

The Master Lock coupler lock is a dedicated trailer security device engineered specifically for RV owners and camper enthusiasts who need to protect their travel trailers, fifth wheels, and utility trailers from theft when left unattended at campgrounds, storage facilities, or driveways. Designed to fit directly over the trailer's coupler mechanism, this lock prevents the hitch ball from being connected to a tow vehicle, effectively immobilizing the trailer and making it impossible for would-be thieves to simply hook up and drive away. Constructed from hardened steel, the lock resists sawing, cutting, and drilling attempts, giving RV owners peace of mind whether they're parked overnight at a rest stop or leaving their camper in storage for the off-season.

Built for the rugged demands of outdoor and roadside use, the Master Lock coupler lock features a weather-resistant housing that shields the internal locking mechanism from rain, snow, mud, and road grime, ensuring reliable operation even after repeated exposure to the elements. The design typically incorporates a pick-resistant cylinder lock paired with a protective cover that shrouds the keyway, preventing moisture intrusion and deterring tampering with lock picks or bump keys. Many RV and camper owners appreciate that the lock is purpose-built to accommodate various coupler sizes, from standard 2-inch couplers found on smaller utility and travel trailers to larger sizes used on bigger fifth-wheel setups, making it a versatile choice for different towing configurations within the RV and camper community.

Ease of use is a key selling point for this coupler lock, as it's designed to be installed and removed quickly without requiring special tools, allowing campers to secure their rigs in seconds before walking away to enjoy their destination. The bright, high-visibility color scheme often used in Master Lock's coupler lock lineup serves a dual purpose: it acts as a visual theft deterrent, signaling to potential thieves that the trailer is protected, while also making the lock easy to spot when it's time to hitch back up and hit the road. For RV and camper owners who frequently travel to unfamiliar campgrounds, boondock in remote areas, or store their trailers in shared or semi-public spaces, this coupler lock offers a straightforward, dependable layer of security that integrates seamlessly into their regular towing and parking routine.

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