Flow Control Valve- Blowsion stocks both 3/8 adjustable (pro version) and 3/8 non-adjustable Flow Control Valves. This Jetworks 3/8" valve has been designed to prevent water flow to the waterbox at idle and off idle engine speeds. This allows the craft to be more responsive off the line and around turns. Results are HUGE gains in throttle response. All stainless internal parts. IJSBA race legal.