External Thread and nut are left hand threads. Internal thread is FPT. For use with tanks having a wall thickness of 1/16" to 1/2". Material - Body and Nut are either Nylon (N) or Polypropylene (P) Friction washer is Polyethylene, sealing washer is either Buna (B) or EPDM (E). Nylon, Buna, and Polyethylene used in manu