PP. With PP stopcock and screw cap (83 mm). TPE gasket. Use for storing and dispensing solutions, media. Ideal for sterile water storage - can be autoclaved before refilling to stop recurring algae or bacterial growth. Excellent chemical resistance. Graduated to deliver in 1-gal and 5-l increments. Stopcock boss molded in one piece with bottle, for strength and leak resistance. Leakproof. PP. With PP stopcock and screw cap (83 mm). TPE gasket. Use for storing and dispensing solutions, media. Ideal for sterile water storage - can be autoclaved before refilling to stop recurring algae or bacterial growth. Excellent chemical resistance. Graduated to deliver in 1-gal and 5-l increments. Stopcock boss molded in one piece with bottle, for strength and leak resistance. Leakproof.