Features: A quick and easy way to connect and solder wires without the need of professional help. It is made of high-quality polyolefin tube and thin copper, making it safe, durable and long lasting. It is waterproof and very suitable for marine and automotive applications. The hot meal adhesive inside the butt connector can increase the pull-out strength and provide sealing, strain relief, cable check and insulation. Working temperature: -55—125 degrees Celsius; initial shrinkage temperature: 80 degrees Celsius; solder melting temperature: 138 degrees Celsius; solder complete melting temperature: 160 degrees Celsius Specification: Material: polyolefintinned copper Colors and size: Red connector: Fit cable / wire size 22-16; AWG 0.5-1.5 square mm Blue connector: Fit cable / wire size 16-12; AWG 1.5-2.5 square mm Yellow connector: Fit cable / wire size12-10; AWG 4.0 square mm White connector: Fit cable / wire size 26-24 ; AWG 0.25-0.34 square mm Package List: Choice 1: 50PCS red 23, blue 12, white 10, yellow 5 x Wire Connectors Choice 2: 100PCS box red 35, blue 30, white 25, yellow 10 x Wire Connectors Choice 3: 250PCS red 100, blue 90, white 40, yellow 20 x Wire Connectors