Natural Rubber type "C" inflatable pipe plugs The "C" Inflatable pipe plugs are fabricated form the finest quality- Natural rubber and are totally vulcanized. No adhesives or cements are ever used. Bladders are then encased in a 100% Polyester cloth cover. All cover seams are triple sewn. The thickness of the rubber and polyester cloth vary according to the size of each plug. Every plug is expertly manufactured to insure a snug fit thus assuring a secure shut-off of the pipe when inflated. All inflating valves and fittings are Brass and Stainless Steel and are standard with each type "C" plug. No parts can rust. 0-15 lb. (1bar) air pressure gauges are required to insure plugs are not over inflated which can be furnished upon request