3/8 13 MM ON/OFF VALVE SHUT OFF INLINE HHO DRY CELL HYDROGEN GENERATOR FUEL GAS Completely close or completely opens great 3/8 shutoff valve top quality perfect for HHO drain tubes on/off valve heavy duty use to reduce amount of vacuum going to reservoir as well Don't Just Buy Products Join Our Club. We Work With All Members To Get Them Results $89 includes membership to our club. Which has installation manuals along with our vehicle database Vehicle database shows all cars we/members have installed on, with their MPG results and how acheived