The hand valve is using the same type of pressure reducer as the pedal.  It can be delivered with or without a pressure gauge showing the output air pressure.  The unit has a lever with adjustable friction, which allows the setting of any engine r.p.m lever between idle and full throttle (WOT) or any air pressure lever.

Part Number without Gauge: 872300, 873300

Part Number with Gauge: 872350, 873350