Excellent product. I use mine on a regular basis especially when shooting with wide angle lenses. It is a lot more difficult to correct for wide angle distortion when the horizon is off by a few degrees but with a level image to start with it is much easier to eliminate the undesired effects of barrel distortion. This mounts right on the hotshoe and is a quick and easy level guide. Works much better then the tiny circular bubble level on my tripod and ball head, and much cheaper then the pro levelers.