The valve comes with detents for manual operation with a knob or, alternatively, without detents for automatic operation with a servo or stepper motor. Nonselected ports vent to atmosphere. In an optional configuration with built-in check valves, two, three, four, five, or six input ports can be switched to a single output port, commonly used to sample pressure readings at multiple locations and feed them to a common pressure gage. This eliminates the need for multiple gages. Nonselected ports are sealed to prevent leakage. Valve-head OD is about 1 in. and length depends on the choice of tube fittings, though typical length is about 1.6 in.