We have a choice to carry one of two optics on our SRT rifles. Aimpoint (mostly PRO), which has unbelievable battery life-It can be left on with no worry about draining the battery, and Eotech (I carry a 518 on my M-4). We have found both to be really sturdy, and nearly indestructible. Bi-weekly training with inadvertent bumps and knocks and they hold their zero. Great thing about the red dot is that you don't need a perfect cheek weld or eye relief to place accurate fire, as long as you can see the dot and it is on target, you can hit it. Not possible with a scope with crosshairs. Cheek weld and sight picture are more critical.