Allen-Bradley 800MR-D9A Momentary Push Button

Allen-Bradley 800MR-D9A is a 22 mm mushroom-head momentary push-button designed for panel-mount control in industrial equipment. The D9A designation identifies a mushroom head (D) with a yellow actuator (9) and a 1 NO–1 NC contact arrangement (A), providing one normally open and one normally closed path for actuation. The round operator is paired with a grey bezel and uses the standard 22 mm mounting footprint common to the 800MR family, and the unit is non-illuminated, intended for simple start/stop and reset-type control signals in PLC- or relay-based circuits. Momentary action means the contacts return to the open state when the button is released, enabling short, pulse-like inputs in automation sequences. This configuration supports wiring in straightforward control circuits where a single push-button input triggers a defined action through both an NO and NC path.