Offered is a lot of (3) Hickok Tube Tester Adjustment Knobs. Each is clean and in good condition with minimal grime. They are used on several Hickok Tube Testers. Each has its setscrew within. Used for many controls on the front of the popular Hickok Tube Testers as well as on other test gear, radios and amps by many manufacturers. Pick up the knobs for your own unit missing a few. Mouse over the photo images to zoom in. NO RESERVE!! Thanks for looking.