Use this circular Bluetooth Focus Controller from PDMOVIE to control fine lens focus with a separately available PD-BTMP motor using Bluetooth from up to 328' away. This compact focus controller mounts onto your cage or rig using a 1/4"-20 screw, and it provides A/B stops, gear direction control, automatic calibration, and it can even be switched to zoom mode to be used as a zoom controller. The controller is powered using a replaceable, rechargeable LIR2477 Li-ion battery.