The Bendix+ M-40QR (quick release) and M-40HF (high flow) pressure modulator valves (PMVs) are high-capacity, on/off air valves that incorporate a pair of electrical solenoids for control. The solenoids provide the electro-pneumatic interface between the vehicle's electronic control system and the air brake system. For example, the PMV is used to control the braking function of service actuators during antilock activity.