Best lightweight red dot available. - Aimpoint Micro T-1 2 MOA Red Dot Sight

I've been using an Aimpoint T-1 Micro for over 15 years. The sight has never failed, never needs adjusting, and the battery lasts for years. I leave the sight on all the time, and just change out the battery every year on my birthday. Last week I was consistently hitting a 24" steel plate at 420 yards with a 14.5" AR15 topped with my new Aimpoint Micro T-1. Basically if you can see it, you can hit it with this sight (assuming you can shoot well). The only drawback to the Aimpoint is that with zero magnification, you can't identify targets past 100 yards or so, depending on how good your eyes are. For a do-it-all close-quarters defensive carbine, there is no better option. I use the Tango Down IO cover to protect it from bumps and scratches and I've found that works well. The sight is costly, but it's one of the few products where you truly get your money's worth. A+ product, highly recommended.