The 1/2” Under-Sink To 3/4” Garden Tap Adapter is designed to allow the 1/2″ under-sink connection, included as standard with all RO/DI systems, to be connected directly to a standard 3/4″ garden tap. The adapter, made from stainless steel, comes standard with a rubber o-ring on the female 3/4″ connection to ensure a watertight seal.