Quality plastic knobs fit 6mm and 1/4" potentiometer shafts Overall Size: 40 x 20mm/ 1.6" x 0.8"(L*H), Weight: 40g ,,Package Included: 4 x Potentiometer Knob This is a set of two black plastic potentiometer knobs, in the classic "chickenhead" pointer design. These knobs include a set screw and are intended for use on shafts that have a flattened area for best results. You may need to file a flat are into a knurled shaft (such as our audio pots) to get the tightest/firmest grip. These knobs will fit either a .25" or a 6mm shaft. Please refer to the size diagram to the right for size reference (all measurements are in millimeters, with inches in parentheses). These knobs are manufactured by Eagle Plastic Devices. Please note that the coins and cigar box detail in the photo are for reference only; this product offer includes only two of the pictured knobs. These knobs look great on cigar box guitars, amps, and other homemade instrument creations!