I am now on my second Acro P2 unfortunately and probably the third soon if Aimpoint will warranty this one. My first lost it's dot just before i hit 200 rds. I then had to turn it on after every round because it would shut off. In fairness Aimpoint sent me a replacement very quickly. Just got my second one in tonight and mounted it on my pistol. So far so good but then I install the battery and screw on the battery cap by hand. Ever so carefully to mind the threads and proceed to tighten up the cap with supplied plastic tool. Low and behold my cap is warped or machined incorrectly and pushes the o ring out the side of the optic leaving a gap. Just my luck! Not a dig at Aimpoint because they have been great so far. I am determined to get a working one eventually.