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Keep your cargo safe with the patent-pending UCS-81A, the most innovate lock in trailer security. The UCS-81A is built to secure virtually all trailer doors from toy haulers to swinging-door truck trailers. The UCS-81A keeps your cargo safe with its hidden shackle, enclosing the shackle beneath the body of the lock. This cutting-edge design keeps the shackle concealed and the lock impervious to bolt cutter and hacksaws. With all aluminum, stainless steel, and brass components, this lock is built to last.

Swinging door, reefer, car, horse, and equipment trailers can all be locked up with PACLOCK UCS locks. PACLOCK also allows you to secure your toys in your toy hauler.

All PACLOCK padlocks come standard with 6-pin cylinder technology.  padlocks only have 4-pins, leaving them relatively easy to pick and making duplicate key combinations a problem. Our standard 6-pin cylinder far exceeds the U.S. military lock requirements of a 5-pin cylinder. The insides of our locks are built using brass, aluminum, and stainless steel components, keeping them secure from not just unwanted guests, but harsh weather as well.

Along with being truly secure and having long-lasting durability, PACLOCK’S Universal Cylinder System padlocks can be keyed-alike, master-keyed, and even grand-master-keyed to minimize the number of keys you need to carry around.

Features & Options


  • Universal Cylinder System
  • Available in PACLOCK Blue
  • Assembled in the U.S.
  • No shackle to cut!
  • 6-Pin, True-Security Serrated, and Spool Top Pins
  • Keys included: 2
  • Country of origin: USA
  • TAA compliant

Available Options

  • Keyed-Alike, Master-Keyed, or Grand Master-Keyed

Specs & Dimensions


  • Body material: Aluminum
  • Body width: 2-1/2″
  • Shackle material: No shackle to cut!
  • Cylinder: UCS 6-Pin True Security Cylinder