Thermosleeve Heat Shrink Tubing 3/16" "Black" - 100 FT by Thermosleeve. $10.80. Thermosleeve HST Series tubing is Halogen-free, flexible, flame retardant heat-shrinkable tubing. This tubing is free of Pb,Cd, Hg,Cr+6, PBB and PBDE.Thermosleeve HST can be used in any enclosed area where a flame-retardant, halogen-free environment is required, such as Metro, skyscraper, mass transit vehicles and ships. The product is UL recognized at 600V and the file No is E180908. All are F mark.