MARRETTE® XTP® wire connector for circuits up to 300 V only. Made of tough, durable polypropylene and 105 °C rated to withstand high installation pressures. POSI-GRIP® surface combines a matte finish with closely-spaced, deep grooves for superior twisting power, even when hands are greasy or damp. Deep, wide throat ensures full insulation coverage. Threaded entry helps guide large wire bundles into the spring chamber. Exclusive Live Action® variable volume spring expands to accommodate more wires with less twisting effort, compared to other connectors with a fixed spring design. Unique copper-coated spring helps resist corrosion. For copper conductor only.