Secure your connections with the TECHSPAN Dome Connector. This grey connector features a 0.750 inch NPT thread and is designed for cable diameters ranging from 0.35 to 0.63 inches. It comes complete with an O-ring and locknut for a reliable and tight seal.The TECHSPAN Dome Connector (RDC21NR-GR) is a grey connector with a 0.750 inch NPT thread. It is suitable for cable diameters between 0.35 and 0.63 inches and includes an O-ring and locknut for installation.