Plug follower

Plug followers are tools used in the rekeying of pin tumbler locks. They are made of metal or plastic, and have a cylindrical shape. The diameter of most plug followers is .495 to .500 inches, but can vary depending on the brand of lock cylinder the follower is being used with. The plug follower slides into a cylinder housing at the same time the cylinder plug is being removed. This prevents the top pins and springs from falling out of the cylinder housing and therefore speeds up the rekeying process.