"The simplest and best-designed 45-degree mini red-dot mount I’ve ever seen comes from Predator Tactical, started by professional shooter Matt Burkett.  Burkett has won just about every 3-Gun title there is, and PT’s Gen 2 Burkett Offset mount has everything you need and nothing you don’t to mount a mini red-dot to your rifle as a back-up sight.  Note that I said rifle, not main optic, because the Predator Tactical Gen 2 Offset Mount has a quick detach base which clamps directly onto the top rail of your AR.  It is low enough (protruding just 3/8” above the rail) to fit under any optic you might be using, and is entirely constructed of thick 4140 hard-anodized aluminum.

If you want to switch main optics, go right ahead, the beauty of the PT design is that it is an independent mount, and it is reversible for left or right side mounting—in fact, it can be mounted anywhere there is a rail.  The mount features a platform on the side tilted at exactly a 45-degree angle with wings on either side to protect the mini red-dot.  It is beefy, but because of its size it still only weighs 4 ounces.  There are versions of the Gen 2 Burkett Offset Mount to fit just about every brand of mini red-dot including most new models (such as the Trijicon RMR), and I obtained one which fit the Insight MRDS I had on hand.  The mount retails for $139.95.

Shooting an AR with an angle-mounted mini red-dot sight does not feel normal in your hands, on your shoulder, or to your eyes, but it does not feel nearly as wrong as you might think, either. You probably won’t be able to wring the kind of accuracy out of it as you would with the same sight mounted directly atop the rifle, but remember, this is a back-up sighing system to be used at distances too close to use your main optic.  As such, this system works very well, and the Predator Tactical Gen 2 offset Mount is the best of the breed."(Jim Tarr - Shotgun News Dec. 5th, 2011)