FIRE RETARDANT HEAT SHRINK TUBING. Type HS-FR is a flexible polyvinyl chloride thin-wall heat-shrink. Offering insulating, color identification and strain relieving properties for terminations and splices. The 2:1 shrink ratio allows for faster shrink recovery, covering wire sizes: #16 AWG to 1000 kcmil. UL recognized, 105 deg C, 600V, operating temperatures from -20 deg C to 105 deg C with a shrink temperature of 135 deg C.