Premium Transparent Nylon 6/6 Insulation allows for easy installation and inspection of wire connectivity 100% Pure Copper Cores with tin plating to resist corrosion ensuring extended life and durability - Weather Resistant RoHS Compliant & UL Approved – 600 V – Temperature: 221°F (105°C) Check our catalog - Available in wide range on gauges and quantities High Quality Nylon Butt Connectors are insulated and can be used to extend the life of, repair, replace or change an existing electrical circuit. These Butt Connectors are made using tinned copper for high conductivity and are wrapped in a semi-transparent nylon insulated case that holds up to higher temperatures and crimp better than vinyl insulated butt connectors. Perfect for use in automotive, marine, home, office, hydraulic, and diesel electrical systems, as well as other high voltage systems. They are rated for use in splicing wires that can carry up to 600 volts with a temperature rating of 221°F (105°C). They are color coded depending on the wire gauge and size and can be crimped using any standard insulated electrical wire crimper. Sizes and colors range from: 4 gauge (yellow), 8 gauge (red), 22-18 (yellow) gauge, 16-14 gauge (blue), and 12-10 gauge (red).