Purchased a Primary Arms red dot 12/4 and went to the range to zero. After a few shots the red dot disappeared. Then the dot would appear and disappear after shots, then the dot started fading then reappearing. Took it home checked the battery and all appeared good as the dot was now staying on. Was at the range today and decided to zero the dot. Turned it on and the dot was there, get on line to zero and the dot is gone. Just so happens that the range is right around the corner from Primary Arms. Dropped in with the red dot and received excellent customer server. The red dot was replaced for a new one after verifying the dot did appear and working properly. Will let you know how it goes when zeroing the new red dot. Thanks again.