These multi-range hex-head connectors cover 95% of everyday applications making them the simple choice for all of your wire connection needs. Don't worry about using a hex tool to install - you can't over-torque this connector because it's patented hex-head design strips out at UL torque saving the wires and your fingers. Inside the connector a zinc-plated square wire spring ensures a secure connection that resists corrosion. The thermoplastic shell is designed for long-lasting strength and resists chemicals while the deep skirt supports smooth wire entry and coverage of stripped wires. Use for: Large appliances, Timers, Indoor lighting, Switches, Ballasts, Junction Box, Air conditionersHex head design allows for automatic or manual installation without stress distortionPatented design can't be over-torqued, strips out at UL torque5/16" or 7/16" hex driver installation optionStreamlined design for compact installationsSquare wire spring grabs and holds wires for secure connectionsLong skirt covers stripped wiresRated at 600V max in building wire and at 1000V max in lighting, fixtures/luminaries and signsCopper to copper connections only