NEF Heat Shrink Solder Electrical Butt Connectors, Red 22-18 gauge, 25 Pack 22-18 gauge red heat shrink solder electrical butt connectors - 25 pieces Translucent, adhesive-lined polyolefin tubing allows visual inspection, prevents wire corrosion, and provides a waterproof seal. Easy installation with pre-measured solder takes the guesswork out of the soldering process. A soldered electrical connection provides superior current flow and tensile strength. Color-coded tubing with wire gauge imprint provides easy identification of the correct part for the job