This extension shank is engineered for installations where countertop thickness exceeds the length of a standard faucet mounting shank. The 7/16" thread sizing is the industry standard for most reverse osmosis air gap faucets, non-air gap drinking water faucets, and filtered water dispensers. The brass construction provides durability and corrosion resistance in contact with potable water. Simply thread the FA-EXT onto your existing faucet shank before inserting through the countertop, then secure with the included coupling nut from below. Common applications include granite counters, butcher block, layered laminate, and stone composite surfaces where standard faucet shanks fall short of the underside mounting area.