The ARRI BigBee Focus Unit add remote focus control to the BigBee Motorized Yoke's capabilities. It works with ARRIMAX 18/12, ARRI Daylight 18/12, Compact 6000, Compact 12000, ARRISUN 120, Studio T12, Studio T24 and M40 lights. It also works with the M90 HMI with the addition of an adapter (L2.0003970).