TENOB Self Bailer Bungs – Internal Mount 35mm ID Black TENOB large nylon self bailers feature a nitrile one-way diaphragm which is unaffected by petrol, diesel or oil. It also includes a bung sealing plug. The self bailer is available in 2 versions. External mount – mounts externally outside the boat as with normal drain plugs for standard self-bailing. Internal mount – mounts internally on the boat : ideal for cockpit draining and for dinghies and inflatables as plug is readily accessible. Flow rate – 500 litres per hour. Colour – black. 35mm I.D drain hole. Drill a 41mm mounting hole.