4 Pack Foldable Book Stand Plastic Book, Clips for Reading Book with Page Holder, Easy to Read and Hands Free Reading

This is a good bookmark when you are in the middle of the book but doesn't work very well when you are at the beginning or the end of a book, especially a paperback. It's ok.

These aren’t amazing. They’re fairly functional. Changing the page is an annoying adventure.

I guess this would work for thinner, non-hardcover books. I could not get it to work for reading hard cover books while in the treadmill at the gym. I ended up returning the product.