Precision molded polypropylene is reinforced with fiberglass for additional strength. Self-aligning ball moves freely against the PTFE seats for smooth operation. The valve opens and closes with very little pressure onthe handle. Ball is diamond turned, after molding, to make it spherically perfect, which provides precise contact between ball and seats. PTFE self-lubricating stem bushings and seats cannot stick or bind. Stainless steel bolts. FKM (viton type) seals.