Heat Shrink Tubing Kit Heat shrinkable tube is made of high quality soft crosslinked polyolefin material, which has the advantages of insulation, corrosion resistance, wear resistance, low melting point, waterproofing, sealing and high adhesion. Package Included: 1x Packing bag 42pcs Heat Shrink Tubes（6 pcs for each of 7 colors Heat Shrink Tubes） Specification: Color: BlackRedGreenYellowBlueWhiteClear ID: 4mm Length: 45mm Material: Polyolefin Flame Retardance: VW-1 Cross-Section Shape: Round Shrinkage Ratio: 2:1 ( The maximum shrinkage rate is 50 Percent of the original tube diameter. ) Minimum Shrinkage Temp: 158 Degree Fahrenheit Full Shrinkage Temp: 257 Degree Fahrenheit maximum Ambient Temperature:-58 to 302 Degree Fahrenheit Heat Shrink Tube is used for electrical insulation, strain relief, solder joint protection, group lines marking, corrosion protection. Heat Shrinkable Tube is very suitable for radio circuit control DIY enthusiasts, allowing your circuit control ideas to be perfectly realized.