Casio F-91W real or fake? white LED? 

Great review!!!

I would say that they are both authentic watches. They have the right screws and when you look at the displays at angle, you can read them clearly and usually the fakes when you put the display out of angle, you cannot read the letters clearly. When you pop the cover, they look exactly the same. Only other sign would be that Casio uses a quality battery And a uses a generic battery. But I would say that they are both authentic.

There’s two other ways to tell the fakes aswell, you can hold down the light button till Casio appears on the screen( Although a lot of dupes copy that) or you can do an lcd test by holding down all three buttons and compare them side by side to check differences

I was going to say fake with that backlight but all of the fakes seem to have completely different modules in them. The module really does look exactly the same as your other one (and mine too). No idea honestly. Also, PUR likely refers to polyurethane which is probably what the strap is made out of.

I have no idea if it’s fake, but the white LED and the dot have Me suspicious. Interested to find out for sure 👍