Sealed red dot - Holosun HE509T Reflex Optical Red Dot Sight

I think this is the game changer for RDS on pistols. I have an open emitter that doesn't work when it gets fogged, mud or snow on the emitter. That can't happen to this. I use the circle dot so there is more chance for me to pick up the reticle if I'm out of alignment. If your eyes are getting old like mine you will love this sight. The down sides are slower acquisition, holster compatibility, electronic dependence and slight visual distortion from the glass. All worth the advantages.