19 P/N:8023488FlushMaster On/OffHandpiece FlowControlsAir BrakeAir CoolantWater CoolantFigure 11 DE-5 delivery headDrive AirPressure GaugeMaster On/Off: This toggle switch activater the air & water shut-offvalves,which control the air and water supplies to the unit.Flush: This toggle is used to purge the coolant water from the handpiecetubing.Hold the handpiece tubing over a suitable container,then activate andhold the toggle for at least 30 seconds to flush out the handpieces.User's Manual of Beyond 300/301 Delivery System6 Functions introduction6.1 Valves layout of delivery headSyringe air controlSyringe water control6.2 Functions introduction