Focus and zoom with your DSLR on the move and get a clearer shot because I don't have to reach for the lens.Movo mff400 is well made and my Cannon 5d fits very well.The only issue I had was that the specific lens I was using limited focus and zoom were swapped on the lens so I just swapped the motors and the problem was solved.I used it for the first time at a worship concert and it worked flawlessly.However I would definitely add some weight in the back to offset the weight. I would also like to see variable speed controls built into the zoom and focus the slower projects I do. Overall a well made product