Black Heat Shrink Tubing: The heat shrink cable sleeve has excellent flame retardant and insulating properties. The heat shrink tubing shrinks quickly and the shrinkage temperature is low. Soft and flexible, fast shrinkage, acid and alkali resistance, anti-aging. 650 Pcs Heat Shrink Tube Kit, 8 Sizes: There are 650 black heat shrink tubes in the transparent box. Provide inner diameter: 150pcs*1mm, 120pcs*2mm, 100pcs*3mm, 90pcs*4mm, 60pcs*5mm, 45pcs*6mm, 30*8mm, 30pcs*10mm. Wide Application: Heat shrink tube covers the wire gauges you will need for RC hobby and many other applications. Effective for insulating or protecting cables in industry or at home, also useful for repairing injured tubing. Also an ideal gift for your father and mother on Thanksgiving Day, Christmas Covers all wire specifications required in a wide range of applications. It is mainly used in wire connections, corrosion protection and rust protection of solder joints, protection and insulation of electronic components of line segment and wire harness. How to use? Select the appropriate size. Insert the wires into the heat shrink tubing. Use the heat gun or lighter to shrink the tube. Do not touch the tube until it is completely cooled. Note: Keep a distance of about 1/2 inch when using the lighter to shrink the tube, otherwise it may leave a black mark on the tube.