The?Intermittent Suction Unit (ISU)?has a mode selection for intermittent, off, and continuous suction. Intermittent mode utilizes a pneumatic logic device to cycle the unit automatically, returning the system to atmosphere in the “OFF” cycle and from 0 to Full Vac in the “ON” cycle. Timing cycles are adjustable from 3 to 30 seconds. Intermittent flow rate shall be adjustable from 0 to 13 Lpm, preset at 8 Lpm. Both mode selector and vacuum regular controls are lockable. The regulator module and gauge assembly are interchangeable with the Continuous Vacuum Regulator. Gauge face has color coded ranges, glow in the dark needle and increments.