This box is also great for adding Remote Focus Pull. Obviously, it works best with a team (or at least two people) if you want someone to be the center of attention. Works with Aircross 2 (I assume it works with all Moza gimbals but I use it with Aircross 2). I bought it to use with my stabilizer. :one. Have distant focus for another person.2. To be able to do "Dolly-Zoom" or "Hitchcock-Zoom" (which requires two focus motors)3. To be able to conveniently adjust the focus/zoom of my camera when I'm on a tripod4. Set focus points on "nail", focus scenes in the rack OVERVIEW: The device works great. Very little lag (if noticeable at all). You can set entry and exit focus points. one of the main reasons I bought it) - Has an informative display - Decent battery life - and easily attaches to a tripod handle. focus and I focus m are focus motors. However, if you want to work standalone, you will need I focus as it has its own battery and can work independently from the gimbal. ALSO: If you're considering a tracking focus system. I would recommend the Original Focus Motor I (standalone) as it gives you more flexibility. However, it is a bit larger. and requires a handheld device (at the time of this review, there are plans to get it working with Bluetooth as far as I know, which I think means it can be controlled by phone). If you don't plan on ever using it other than a gimbal. Then just choose I Focus M. It's smaller and cheaper. Either way, you should be happy with its performance. I.