The Eaz-Lift Small Coupler Lock Pin with Saver Chain allows you to keep your trailer latch securely fastened to the trailer ball. The provided saver chain attaches to your coupler for additional security. It has a pin diameter of 1/4-inches with a usable length of 1-3/8-inches. The coupler lock pin has a round shaped retainer pin that allows enough clearance for the coupler latch. Constructed of zinc-plated steel that is corrosion resistant.