The Amphenol T series SwitchPlug uses a unique 360 degree precision sliding helical spring contact design to quietly and accurately switch the signal circuit safely to ground during instrument changes under load, thereby avoiding annoying thumps, pops and squeals. The sliding ring contact self-cleans every time the plug is connected preventing excessive build up of oxidization and contamination. Activation is directly off the jacks full front face assuring a positive reference point every time, and as it works instantaneously on the main circuits there is no need for the use of magnets or other elaborate switching mechanisms. Thermoplastic Backshell. Straight, black finish. Large cable clamp.