I have an almost brand new Habrok Pro HQ50L with exactly the same problem. I used mine for less than 6 hrs over two stalks and the right hand eyepiece became loose and would not stay in its position ( the eyepieces slide for eye width, but can not be locked in position by their design ). Mine was so bad I contacted HikMicro who wanted to repair them, I wanted a replacement pair as they were so new, but was refused when dealing with the online Hikmicro customer support . I returned the Habroks to the dealer who sent them back to Hikmicro UK, requesting replacement rather than repair, this was done while I was out of the country. The Habroks were returned to the dealer within a week but they only repaired and replaced the eyepieces, the unit was not replaced as requested. I find this very poor considering the Habroks h