Offered is the original Rotary Plate Adjustment Control from the Heathkit TC-1 Tube Tester.  This is a low wattage wirewound potentiometer, it is in working condition-it rotates freely and checks out on the ohm-meter. It is by Centralab, but bears no part number. The resistive element within measures about 220 ohms on my DMM. The control is for a 3/8 inch panel mounting hole. Original knob, mounting nuts and washers included.  Tiny wire pigtails remain for color reference in replacement use-these can be easily removed.  Pick up the Plate Control Pot for your own Tester requiring a replacement or for another tester-these controls were used in many many tube testers.  Mouse over the photo to zoom in. NO RESERVE!! Thanks for looking.