Progressive Square Head Male Gate Locking Pin With 4-3/4" Long x 1/2" Diameter, specially designed for manual or mechanical gates with a high security padlock, securing the gate in a down and locked position. This pin locks a gate by passing through the gate channel rail and the gate slat, and locking a padlock through the gate pin head and the gate. A 1/2" Drill hole should be drilled in the channel rail and the corresponding slat, so that the pin can enter. Make sure to check the size of the padlock, because the square head has a 9/16" hole allowing for a padlock to attach to the gate.