HIGH QUALITY - 100% pure brass core, chrome-plated hardened steel, high quality tubular key, make this product durable. 5/8" DIAMETER PIN - 3-1/2 inch(16mm) pin I/II maximum load rating: 3500 pounds, 5/8 inch(16mm) pin III/IV maximum load rating: 10000 pounds. UNIQUE DESIGN - 1/4 Turn lock and push lock design, so that it can be quickly installed and removed. ALL-WEATHER RUBBER CAP - The deep layered cap and grip provides extra protection against corrosion and gunk during extreme weather. AUTO-RELEASE AND LOCK - Turn the key 1/4 of the way and the lock automatically releases from the pin. Frustration-free and quick installation!