Merrill Manufacturing Pitless Adapters have passed CERTIFIED WATERTIGHT STANDARDS PAS-1, PAS-97(2019), ASSE Standard #1093-2019 established and regulated for the industry by the Pitless Adapter Division of Water Systems Council. Bottom of the Male Part and the Top of the Female are Tapered - Seemless connection and easy removal Replaceable O-Ring Seal - Easily replaced, not a factory only seal Molded Gasket - Positive outside seal on discharge, plus O-Ring or gasket glued in place for the seal on inside of the casing Stainless Steel Collar - Perfect fit and positive seal with a molded gasket between discharge and outside of the casing. Ensures sanitary watertight seal to the casing Extra-Wide Stainless Steel Nut - Accommodates wrench for easier installation *When properly installed, Merrill pitless adapters will support the length of schedule 40 steel pipe full of water and pump.