The quickest easiest upgrade in the history of accuracy. The Mepro microRDS brings the rapid target acquisition of a full-size red dot rifle optic to a compact pistol sight. Featuring a patented quick-detach (QD) adaptor kit that easily mounts using the pistols existing rear sight dovetail slot; no drilling tapping or need for a gunsmith. Its the only red-dot solution that instantly mounts and dismounts without having to re-zero with an adaptor that also gives you a Meprolight TruDot self-illuminated sight as a back-up when the red dot optic is removed. Built to mount in minutes to any pistol with red dot capability. It also serves as an excellent close-quarters red dot sight and backup sight for rifles and shotguns. 8.5 hours auto shut down. Sig P-Series Dovetailed #8 rear/#8 Front Sight.