This is a Micro Red/Green dot scope with a high mount.  The picture shows the low mount but it comes with the hight mount (with quick release) for AR's, high tube shotguns, etc.  We've tried it on 22's, 223's, 7.62x39's, a Rem 870 and a few hunting rifles and it works great.  It is similar to an Aimpoint Micro T-1.