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Master #377 Universal Coupler Lock


  • Fits many 1-7/8" and 2" couplers.
  • Adjusts to fit many makes and models.
  • Will NOT fit couplers that do not have a lip, such as Bulldog® couplers.
  • Each lock comes with 2 keys.

MSRP = $53.00 / $44.17 for KA

The Master 377 has been a mainstay of the Master trailer coupler lock line for years and is still a popular choice. Just be sure your trailer coupler has a lip for it to lock over. ie. The Master 377 lock WILL NOT work on Bulldog couplers.

Uses a Master K1 Key. Master Lock no longer offers this lock in keyed-alike. Sorry. .
Master K1 Keyway Comes with 2 Keys

Add to Cart:

  • Model: MA-377
  • Shipping Weight: 3.75lbs
  • Manufactured by: Master Lock
  • UPC: 0-71649-04795-4

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If ordering more than 1 of these locks


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