I have tested quite a few magnifiers for fishing. Many are let down by poor design, with one quite expensive set it was not possible to view close objects as the lenses are too far apart and your eyes end up looking between the lenses. These magnifiers work really well, they give a good working distance and can attach to either your fishing cap or fishing polarizer glasses. When used on a cap they can be flipped up out of the way when you're not using them. They also come with 3 different strength lenses.
Key Points:
We now stock also stock HatEyes as a deluxe option for clip on magnification: