I have the Noga with the 4-1/2" bottom arm and the 4" top arm, with the fine adjustment on the base. The clamp holds either a 3/8" round or an 8mm dovetail mount. It works great on my 10K and should work just as well on a 9". I usually mount it on the cross slide, but it will work on the v-way too, but it's not as stable there. As I recall there is a choice of magnet bases - if so, get the one with the strongest magnet.