HarshMet Cold Shrink Silicone Tube s CPS-CLM Series are open-ended, CLEAR silicone rubber, tubular tubes with built-in mastic . The sleeves are factory expanded and assembled on a removable supporting plastic core. Each rubber assembly is supplied for field installation in this pre-stretched condition. As the core is unwound, the insulating sleeve shrinks to form a tight seal. A wide range of sizes of Cold Shrink tubes cover terminal lug barrels and inline connectors .