The TECHSPAN RDC21AA-GR is a high-quality connector designed for reliable performance. Featuring a PG21 size and a grey finish, this connector is built to accommodate cable diameters ranging from .51 to .71 inches. It comes complete with an O-ring for enhanced sealing and a locknut for secure installation.The TECHSPAN RDC21AA-GR is a PG21 size connector with a grey finish. It is designed to fit cable diameters between .51 and .71 inches. The connector includes an O-ring and a locknut for secure and sealed connections.