Cliff FC1622 K1C Knob Black - Satin Cap - 6mm Screw Fix

Cliff K1C Black Control Knobs - Cliff FC1622, A classically-styled, low-cost black plastic screw fixing knob with a satin disc to suit 6mm shafts. Cliff FC1622 K1C Knob Black - Satin Cap - 6mm Screw Fix

Price: 2.80 from Rapid Online Rapid Electronics Ltd.