How heavy is the A4 mount?

It weighs about 137 to 140 grams, which is light for a helmet night vision mount. That keeps the helmet closer to bare weight and reduces front-heavy balance.

What does three-axis adjustment let me do?

It lets you set the goggle's position on three axes, so you can line up eye relief, height and tilt to your eye. That matters most when the goggle is shared or moved between helmets.

Does it fold out of the way?

Yes. The mount stows in a low-profile position against the helmet, keeping the goggle close to the shell when not in use.

Which helmets and goggles does it fit?

The mount is not described with a specific helmet interface or goggle shoe standard. Check the shoe type on your goggle and the shroud on your helmet before buying.

Is it worth it over a heavier metal mount?

If weight and a slim stowed profile matter most, it is the better fit. If you expect hard impacts and want maximum ruggedness, a heavier metal mount is the safer choice.