WireGardâ„¢ twist-on wire connectors are designed for general-purpose applications requiring the connection of 2 or more copper wires. WireGardâ„¢ connectors feature a straight type polypropylene shell with side knurling for an easy grip. The inner spring is zinc-plated to resist corrosion and has a tight square profile to make quick secure contact with wires and ensure connections with positive continuity. These all-purpose connectors require fewer turns to meet required torque and meet or exceed UL pull out and dielectric test requirements. The tough thermoplastic shell shields against environmental extremes and resists chemical action from hydrocarbons diluted acid or alkaline solutions. The high-dielectric shell also features a deep skirt design to prevent exposure of bare wire. Flame-retardant properties resist heat distortion up to 221 deg F. Color coded for quick and easy size selection.