We had these custom made to fit both our DACT attenuators and the ALPs motorized pots used in our remote control kit. They are aluminum with a matte finish. A clear coat covers the finish.

Only one diameter available. The larger knob is out of stock. The smaller knob is 30mm in diameter. The shaft hole size is 6.08mm which is perfect for the DACT attenuators and works well with the Alps tapered shafts. It will work with 1/4" shafts with a slight boring out of the hole using a 1/4" drill bit. The aluminum is very soft so this is not a difficult operation. A single set screw attaches the knob to the shaft.