These vent plugs are used during the construction of Epoxy surfboards. They provide a spot for the board to vent air and gases. This vent plug is supposed to be installed directly into the EPS foam during the surfboard construction process. To release the gas/air simply unscrew the thumbscrew and wait 5 minutes. The thumbscrew comes with rubber o-ring to keep water out!
Use a 1″ hole saw bit to install plug.