Circular Plastic Connectors (CPC) Protective Caps TE Connectivity's Circular Plastic Connectors (CPC) Protective Caps are designed to fit the existing CPC plugs and receptacles, providing protection from environmental contaminants. These protective caps are disposable, recyclable and feature up to 80°C temperature resistance. The CPC protective caps come in orange, red, black, and yellow. These protective caps are used in robotics, industrial machinery, instrumentation, power supplies, material handling and welding equipment.