Love the big 40mm size and integrated laser - NcSTAR 1x40 Red Dot Sight w/ Built in Red Laser-QR Weaver Mount

I love this red dot sight and its laser. The variable intensity works great in strong daylight. Some reviewers have had problems with it that could be related to its use of a Weaver rail rather than a Picatinny rail. The two rail types look a lot alike but in this specific case the Weaver rail used by this optic fits slightly loose on top of a typical Picatinny rail. You will need a riser that is slightly wider on top or you will need to use something like aluminum foil or epoxy to fill in the extra space. I own several Picatinny risers but only one was just wide enough to give this optic a tight fit.