A bung fitting is a natural/white polyethylene fitting that has an inside diameter of 2" NPT (National Pipe Thread). The fitting is fabricated onto the item prior to shipment and can only be installed using a heat-sealing process. The cap has a 3/4" NPT plug knockout. If the knockout is removed, a 3/4" optional NPT/hose adapter can be used with the fitting. The 3/4" nylon NPT/hose adapter is sold as an accessory to the fitting to allow its use with garden hose.