flip-up magnifiers. I find them so useful. Mine are adjustable up & down so that I can created bifocals to suit my whim. They are so good I spent many hours over one week trying to find them on the web again, even wrote to the original suppliers who no longer sold them. I have repaired them with Araldite & matchsticks twice. They are cosseted in their own padded case, too precious to loose or damage.

You would be amazed if you looked at you guitar bits through them.