What is the width in 130x50x65mm

I was going to buy a holographic sight for my airsoft M4A1 and it has a 20mm rail.

It's length x width x height/depth, so 50 would be the answer.

Length * width * height
So 50 is the answer.

Anyway, none of the above would fit on a 20mm.rail,obviously!

Second figure (50) is the width.

Normally its length x breadth x width(lbh)

So, the width is 65mm

in my experience it goes, length x width x depth

definitely not 130
use common sense to decide between 50 and 65
if u have seen the object u ll know what is the thickness