At 4 inches in diameter, the “keeper” of a magnifying glass is an ideal size for one’s toolbox or desk drawer, taking up little space when not in use and an easy grab when you do need it.

The screws that go in your phone are minuscule, and a magnifying glass is really handy if you want to check out the detail on your 3D prints. While this is easy if you have good eyesight and you ...