Generally they come with flip up covers which you can put down when you flip it to the side. Generally I've found them to be pretty useless. They aren't solid enough to be accurate and are too dark to see targets properly
It's actually a mini reflex with an 11mm dovetail rather than a picatiny so I needed an adapter with then raised the sight. I actually quite like it at that height as it, as you say, helps when I'm wearing a mesh mask but also when I'm wearing electronic ear defenders. I've found with other sights I have to get a much lower cheek weld which means I knock the ear defenders and it gets really annoying. I think it puts the reticule around the same height or slightly higher than a T1 with a riser.
Oops...
VFC HK417 AEG with accessories. There goes my airsoft budget for this month and the next few will all be spent on new motor, inner barrel, hop up, piston assembly, air nozzle, cylinder head and Gate Titan.
Finally got my SRC TCC M4 to a point that it works and looks good doing it.
When I first got it the wiring was perishing, the shimming was pretty terrible and the air seal was non existent. A reshim, rewire, new O ring and a MOSFET later and everything's working smoothly and I have a new rail system, pistol grip and stock.