8-pack Potentiometer Knobs: Flat-Top Knurled Black Quality glossy black metal knobs fit 6mm and 1/4" potentiometer shafts Great as guitar and amplifier knobs and for general electronic usage Also work great for cigar box guitars and amplifiers Attractive black exterior with a plastic insert inside that grips knurled pot. shafts Distinctive flat-top shape great for all kinds of projects