Push-in wire connector to join and insulate 2 wires No-twist design reduces repetitive motion fatigue Minimum capacity of four # 20 solid wires, Maximum capacity of four # 12 solid wires Stranded wire range: # 16 - # 12 AWG (19 strand) and # 18 AWG (7 strand), Tin bonded stranded wire range: # 18 - # 14 AWG (19 strand) Product Specifications: Clear shell gives visual verification of your connection, Rated to 600-Volt maximum, Tough, UL 94V-2 flame-retardant shell rated at 105 C (221 F), UL listed to 486C CSA certified to C22.2 #188