This full sheet magnifier is a great idea but... it’s of fairly low quality and the entire sheet does not magnify equally. I would ask if you can try it in-store before you buy it. In other words “buyer beware”.
It works ok if you have something to hold it with (a clip or something) above or in front of what you want to magnify but it is too cumbersome to hand hold in order to read a book or magazine. I'd like one about half that size but could not find one.
Impractical for me... Returning it. (Have to hold to get best effect!) Great idea but when I need to use it generally for "document" and takes "time" fully evaluate docs... Considering "Mag Light"!