Twist On Wire Connector Color Gray For Conductor Material Copper Maximum Operating Temperature 221 Degrees F Maximum Voltage 600 V Minimum Wire Combination (1) 20 AWG with (1) 18 AWG Maximum Wire Combination (1) 10 AWG with (2) 12 AWG Contact Material Steel UL 94 Flammability Rating V-2 Maximum Conductors 4 Standards CE CSA Certified UL Listed Wire Connector Style Standard Compatible with Product Type Underground Fill Material Silicone Insulation Material Thermoplastic Polyester