1 Inch Bulkhead Fittings, Double Slip Joint *** Builders Pack of 5 Bulkheads *** Heavy-duty bulkhead fittings with gasket for a water-tight seal Fits 1 inch PVC pipe with double slip fitting for both drain and overflow applications Builders Pack of 5 Bulkhead Fittings Just drill a 1-3/4" hole in your reservoir, tighten the nut and you are ready to go Build your own rain barrels, overflows, fish tanks, poultry waterers and more