Linch Pin, 5/16"
Linch pins have various uses, but on a horse trailer, they secure the rear doors of trailers that have a hasp & cam bar method of closure.
We have tested & chosen this size: a strong 5/16" diameter pin that snaps against the 1 7/8" diameter steel ring, and holds the cam bar hasp closed & secure.
Don't take a chance & haul your animals without first securing the hasp with a pin! Attach it to the trailer with a lanyard & screw so it stays on the door.