GB WingGard wire connectors make quick, secure connections with easy-on wing-type design providing positive continuity between conductors. The expandable square wire spring creates a strong vibration-resistant connection. Their tough, thermoplastic shell shields against environmental extremes. The color-coded, high dielectric shell features a deep skirt design to prevent exposure of bare wire while providing superior flash-over protection. Splices copper-to-copper. GB connectors comply with Federal specification W-5-610d and are UL486C listed and CSA (Canadian Standards Association) certified. The connector is flame-retardant, nonporous and noncorrossive, and resists surface cracking and chemical action. Temperature rated to 221 degrees Fahrenheit. UL (Underwriter's Laboratories) listed.