The Autopilot 312-D is a 2" Half Union Slip x Male with an O-Ring. Autopilot has been the leading swimming pool salt chlorine generator manufacturer since 1976, offering a full range of units to meet any chlorine need. AutoPilot® can maintain anything from small above ground pools up to very large commercial facilities. This 2" Half Union Slip x Male with O-Ring is a genuine Autopilot product.