The Speed Bead mount is awesome, I have one on my M2 20 ga. and I am having one modified to fit my daughters Affinity (Burris doesn't make one for a 20 ga. Affinity). Once you get them mounted they are rock solid and the thing I really like about them is if your battery goes dead in your FastFire scope you can sight right down your rib and use the bead, didn't think I would like it in the beginning but after trying it I love it.