NOVA Red Dot Sight, 2 MOA Reflex Sight Pistol Red Dot Scope for 21mm Picatinny Rail Mounts, with 12 Brightness Settings, Red Dot Optics Gun Sights for Rifles| Shake Awake & Waterproof

The red dot looks goodComes with a glock mountThe brightness is goodQuick to installGood quality

The red dot fluctuates from large to small intermittently

I use this red dot for my Glock 18 airsoft gun and its perfect. I didnt have to change the battery for months. The only downside is that it doesnt have a on or off. The button are very sensitive so my red dot just turns on and I don't notice it for hours.

It's nicely made, looks good and feels quite pleasantly solid in the hand. Unfortunately that's where the positives end.Along with the scope, there was a little bag of six different sized allen screws and three different sized allen keys. The box also contained some kind of rubber cover thing for the scope, which was too big and floppy to be of any use, the plate for mounting on the slide and a plastic "key"-type thing for adjusting the windage and elevation screws. And herein lies the problem - it's useless, as some other reviewers have noted. I had to resort to a plastic trim tool, but I didn't need to as the adjusters don't actually do anything. One of them did the little clicking thing when turned, suggesting something was changing, but that's all; it didn't affect the elevation one jot.Similarly, turning the windage adjusting screw also did nothing, but this time minus the clicks.Both adjusters looked like they had already been used, perhaps with a metal screwdriver, which makes me think that perhaps this unit is not quite as new as it's meant to be.Disappointing, and unfortunately this seems to be an increasing experience in buying things from Amazon - so many things arrive faulty out of the box, or don't appear to be new. Or if sent via Royal Mail, don't actually arrive.I'm disappointed in this whole experience and may give-up buying online as it's not what it used to be. Or perhaps it's just that products nowadays are simply rubbish a lot of the time.Oh well....