1.metal knob 2.use for wirewound potentimeterWXD3590 3.potentiometer knob, high quality dial precisely measure 4welcom to ask digital knob and used on 3590s,22mm or 46mmmetal knob that was used on all kinds of multi-turn wireeound potentiometerdiameter:46mmheight:25mmit can be used to turn 10cycles,15cycles,20cycles. metal knobs,precise Electronic components