I bought this red dot with a reasonable expectation that it will do what its supposed to. I installed it to my glock as per the manufacturer instructions. the quality of the screws to adjust height and windage are deplorable. bits of the casting started coming off pretty much immediately. also worth mentioning that the laser dot points way out even at maximum adjustments either way. so no matter how much you adjust one way or the other, the dot will point way out. i reverted back to the original standard sights on the glock. this red dot was an extreme waste of money. very disappointed! spare yourself the agony and save your money. and perhaps seek alternatives out there to this horrendous piece of crap.