Shrink tunnel rod covering material : we can supply ( depending on manufacturer ) full silicone tube or reinforced fiberglass with a  coated/impregnated with a NON-STICK material .
Ultimate goal is not let the heated foil sticking on the steel or aluminium rods.

We can also supply you with coated shrink tunnel rods !

Shrink tunnel rod covering material, Glass coated teflon , Full silicone.