Forgot...
ACOG...the 2x, 3x, 3.5x, and 4x models provide my aging eyes a little needed assistance over about 150rds (the TA47 2x is also works close in...not so much magnification to be a burden. I have a TA11 on my SCAR-17 and TA31 on my SCAR-16. I've owned quite a few other models over the years, but the 11, 31, and 47 are my personal favorites).

