Thermosleeve-USA HST is our most popular series of heat shrink tubing and an excellent choice for many general and commercial applications. Economically priced, HST is very flexible, halogen free, flame retardant tubing made from a special blend of cross-linked polyolefin. Typical applications include strain relief of wire connectors; identifies or color codes wire and terminals; electrically insulates components, terminals and wire splices. HST is resistant to common fluids and solvents and has a shrink temperature rating of 90 degrees C (194 degrees F).