PACLOCK's 77-Series High Security Trailer Coupler Lock for 2-5/16” Bulldog Couplers, UCS, Integrated Stainless-Steel Cone “Puck” Lock, Patented & Patent Pending, Keyed Alike U-Pick!

Secure your trailer with confidence. The “UCS-77S-BUL-2516” is PACLOCK’s high-security solution for 2-5/16” Bulldog trailer couplers – engineered from top-grade materials for strength, simplicity, and all-weather reliability. PACLOCK’s patent-pending two-piece design integrates the lock body directly into the protective shroud, eliminating the need for a separate puck. That means faster installs, fewer parts to manage, and less frustration – especially in harsh conditions like rain, mud, or snow. At the heart of the lock is PACLOCK’s patented 304-grade stainless steel cone puck – a customer favorite for its superior corrosion resistance and toughness. Unlike the 303 or 302 grades used by competitors, 304 resists cracking and deformation under hammering and prying. It can also work-harden during poorly executed drilling attempts, making frontal attacks even harder to pull off. The cone shape deflects drill bits before they can grab – a key defense feature. The shrouded ¼-inch steel housing provides added protection from cutting and blunt force attacks. A zinc-plated base layer beneath the powder coating keeps rust at bay – even if the outer finish is damaged. With PACLOCK’s Universal Cylinder System (UCS) and Every Lock, One Key (ELOK) capability, you can key all your PACLOCKs alike – from your coupler to trailer doors, hitch receivers, latch pins, YETI coolers, toolboxes, and more. Innovation That Secures What Matters. PACLOCK builds locks that perform when it counts – smart designs, serious materials, and unmatched versatility for people who take security seriously.

• Protects 2-5/16” Bulldog Couplers: Patent-pending 2-piece system simplifies installs, saves time in harsh weather, & prevents lost pucks. Does not fit standard 2-5/16” couplers, Demco, & Airstream.
• Patented “cone puck” inherently prevents frontal drilling attacks common on traditional hockey-pucks. Paired with industry-leading 304 stainless steel, it is highly resistant to drilling attempts.
• 304 stainless steel puck provides stronger corrosion resistance than common 303/302-grade competitor pucks. Zinc plating beneath the powder coat on the hasp and shroud adds protection against rust.
• Every Lock, One Key: Use one key for all your security solutions – trailer doors, hitch pins, Pelican cases, or cam locks! The pick/bump resistant 6-pin UCS cylinder allows for 20,000+ key codes.
• American Manufacturer: Made in USA with global components by a family manufacturer hiring veterans and people with disabilities. Our product line is growing, so if you don’t see your lock, call us!