TerreMax Nylon Bulkhead Fittings, 3/4 in. Female NPT, Nitrile Rubber - John M. Ellsworth Co. Inc.
4" Bulkhead Tank Fitting - PVC
Amazon.com: PVC Bulkhead Fitting Double Threaded Bulkhead Water Tank Connector for Rain Barrels, Aquariums, Water Tanks, Tubs, Pools, Spigot, Black, 3/4 Inch Male 1/2 Inch Female (4 Pieces) : Industrial & Scientific