This board is a Port interface including a solenoid valve for liquid reward delivery. It connects Bpod Finite State Machine via an Ethernet cable, to a behavior port mounted inside your experimental chamber. It is compact enough to mount vertically behind adjacent ports that are 5mm apart. The board contains a thumbwheel potentiometer wired to adjust the current (and consequently, brightness) of the port LED. This allows the experimenter to calibrate the maximum brightness of multiple ports. The board comes with a 3D printed mount, for convenient attachment to the Bpod mouse behavior box.