These insolation is flame-retardant and could be used in variouse scenarios. We designed and manufactured it with the purpose of long time of using. With its extraordinary durability, this product could be serving you well for years to come. For electricians, this set of would be indispensable. Features - Color: Assorted color. - Material: PE, crosslinked polyethylene. - Size: 17.00X13.00X3.60cm/ 6.68X5.11X1.41inches. - Made of material, safe and durable for lasting use, heat-resistant and flame-retardant. - Multiple sizes heat shrink tubing for your choose. There is always a size that can come in handy when you need to do some wire repair. - Wide application: they can be used for solder joint protection, group of lines marking, capacity reason protection etc. - Our heat shrink tubing has the advantages of good electrical insulation, corrosion resistance and high temperature resistance. - and flexible wire shrink wrap, low shrinkage temperature-minimum shrinkage temp: +158 fahrenheit scale(+70 degree centigrade), fast shrinkage, easy to use heat . Package list: 3 pcs x 180pcs x heat shrink tubes (1.0 x 45mm, black) 3 pcs x 150pcs x heat shrink tubes (1.5 x 45mm, red) 3 pcs x 100pcs x heat shrink tubes (2.0 x 45mm, yellow) 3 pcs x 70pcs x heat shrink tubes (2.5 x 45mm, green) 3 pcs x 50pcs x heat shrink tubes (3.0 x 45mm, black) 3 pcs x 30pcs x heat shrink tubes (3.5 x 45mm, blue) 3 pcs x 40pcs x heat shrink tubes (4.0 x 45mm, red) 3 pcs x 25pcs x heat shrink tubes (5.0 x 45mm, blue) 3 pcs x 25pcs x heat shrink tubes (6.0 x 45mm, blue) 3 pcs x 25pcs x heat shrink tubes (7.0 x 45mm, red) 3 pcs x 25pcs x heat shrink tubes (10.0 x 45mm, black) 3 pcs x 20pcs x heat shrink tubes (13.0 x 45mm, black)