Even the most practiced handyman has a dickens of a time distinguishing between a ¼" and 5/16" nut – especially in the low light under a hood or in a cramped utility closet. Don’t waste time guessing when this handy gizmo can give you a definite answer in no time flat. It’ll help you sort nuts ranging from 5/32" to 1½" as well as the corresponding bolt and wrench size. You can even use it to size that old set of wrenches with numbers too worn to read. Use the magnetic back to stash it in your toolbox or hang out in your shop.