3M makes a bunch of different heat shrink products as well as a "cold shrink" product that doesn't require a heat gun. It's a very stretchy rubber that they hold open mechanically (picture a slinky with a rubber sleeve around it). You pull a cord that hangs out one end and as the thing spools out the rubber shrinks down behind it.
It's sorta hard to explain but it works pretty much like heat shrink without the "heat".
Keith
