Features a fixed, square-wire spring that creates its own threads and maintains a secure positive grip that will not relax over time. There is no pre-twisting required. The positive grip design provides fast and easy installation on 22 to 14 AWG wire. The deep, wide skirt helps protect against flash-over and turned-back strands for maximum dielectric protection. The connector features a tough, UL94V-2 flame-retardant shell rated to 105 deg. C (221deg. F) and is UL 486C listed and CSA 22.2 #188 certified.