Designed to connect to the standard 3/4" NPT connection on a water heater safety expansion tank and provide the means for the tank to be installed on 3/8" to 1" O.D. copper or plastic pipe. Product includes: Brass body, self-piercing pin, NBR rubber gasket, and 3/16" hex wrench. Benefits include substantial reduction to installation time for a new system and simplified installation into an existing system. Helps regulate water heater pressure and prevents damage to the water heater or other appliances caused by water pressure fluctuations, reduces water hammer. Import.