Thogus Polyethylene Tube Fitting, Plug, Black, 1/4" NPT Male (Pack of 10) Plug for closing the end of a pipe or fitting Male NPT threads for connecting to female threaded pipes Polyethylene for its light weight, durability, and barrier to gases, vapors, and moisture Working pressure of up to 150 psi Operating temperatures range from -80 to 200 degrees F