... .Closed-cell flexible 4.Fire proof, MoistureproofBellsafe-flex adopting NBR/PVC as the main raw material, is an environmental product.It ... ,tobacco field ,etc. sponged rubber sheet, rubber sponge sheet/board/ Pipe rubber foam, fireproof apply in HVAC system Specification: Main material ... : NBR/PVC ID size:1/4", 3/8", 1/2", 5/8 ...