Hello. Welcome to Futurlec. The electronic components Superstore. To find the component your looking for, either search by Part Number or visit the relative department. Need Help. KNOBS KNOB22 - Silver Position Plastic Knob Photograph Features Suits 1/4" Shafts Suitable for use with Rotary Potentiometers or Rotary Switches Solid Construction for Durability and Professional Look Knurled Surface for Sensitivity Dimensions: Height - 18mm, Diameter - 29.5mm