It is a braided packing made of pure PTFE thin yarns fiber, almost complete chemical inertia, dimensional stability ... , low frictio It is a braided packing made of pure PTFE thin yarns fiber, almost complete chemical inertia, dimensional ... , rods, pistons valve stems, expansion joints, etc. The packing impregnated with PTFE are also available .Spec: 3.0mm - 50mm Pure PTFE Packing