I had my scope for a couple of months before I put on the electric focuser. I was lucky that when I installed it I had the scope pointed up and, because of previous use, it was not on the end of the screw, so everything went together easily. Now I don’t know what I would do without it. However there is a thing that is irritating about it. There’s no way to turn it off, so if you leave the controller connected to the focuser the 9v battery will run down quickly. What I do is plug in the focuser and focus the image then unplug it. It seems kind of dumb to have to do that but I don’t want to buy a new battery every time I use the scope.