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 KNOB - Black Plastic with Pointer Photograph Features Suits 1/4" Shafts Suitable for use with Rotary Potentiometers or Rotary Switches For Knurled Shafts Dimensions: Height - 15.5, Diameter - 19mm