1-1/2″ NPT Female x 1-1/2″ NST (NH) Male Brass Hexagonal Nipple Fitting Fire
NST also goes by the initials NH or National Hose. It can even be referred to as NHT or National Hose Thread. ◆Hex nipple fitting 1-1/2″ female National Pipe Taper (NPT) threaded connection on one end and a 1-1/2″ male National Standard Thread (NST) or National Hose (NH) connection on the other.