The Heat Shrink Tubing and Sleeves 321-11600 by HellermannTyton is a 3,5:1 Thick wall unlined in 1m lengths black. It is a single wall Polyolefin tubing design that is 6mm in diameter and is perfect for a variety of uses. It can provide maximum insulation protection as well as sealants and strain relief. It is perfect for harness wrapping, sealing of electronic components, and cable jacketing. It has a 3:1 shrink ratio, is RoHS compliant, and meets UL224 specification. This product will not Chlorinate, Aromatic hydrocarbons, or flame retardant chemicals. It can also resist liquids, solvents, dust, and fungus.