Anti blue light screen protector for laptops, monitors and PCs

I found that the frame tabs did not work as fitting them left too large a gap for the overlay to fit close to the vdu screen. I shall be changing over to the alternative method. The privacy facility gave a restricted view on my 2nd screen placed slightly to the left of my main screen. The left and right edges are darker than the centre section. This may change when I change to the other fitting option. The instructions do not mention the protection(?) film on the front.

Says it was for the MacBook Pro 14” 2023 but did not fit the screen at all.

Like that it does work Don’t like that its dark and slides around