The PocketWizard MultiMAX Transceiver uses two "AA"
batteries for power. These will normally last 150 hours,
but if the unit or units' location will be inaccessible
or if used frequently in the studio in the same or similar
positions, an AC adapter can be purchased to power each unit.
Turn the MultiMAX
unit off.
Insert the AC Adapter tip into this port on the left
side and connect the other end to an AC socket.