A spacer separates a threaded self-locking connector adapter from a cable transition piece. When the spacer is in place, the self-locking backshell slides over the transition piece, the spacer and threaded portion of the connector to provide support and shielding for the wires. The spacer includes locking teeth which fit into locking teeth on the connector and transition piece to prevent the connector from rotating relative to transition piece. The transition piece includes a locking detent mechanism. The outer shield of the cable is clamped by a cable clamp. The Shielded wires run through the center of transition piece and the individual shields from the wires are clamped to the transition piece by the clamp.