MARRETTE® wire connector for circuits up to 600 V and lighting fixtures and signs up to 1000 V. Made of tough, durable polypropylene and 105 °C rated to withstand high installation pressures. Deep, wide throat ensures full insulation coverage. Exclusive Live Action™ variable volume spring expands to accommodate more wires with less twisting effort, compared to other connectors. The square wire spring construction and funnel design gives a positive pressure conductor grip for solid or stranded wires . For copper conductor only.