Set consists of two Volume Knobs and one smaller Tone knob. Black molded phenolic plastic with white indicator line. Slotted set screw fixing to standard 1/4" USA or import 6mm solid shaft pots. Volume knob diameter at bottom .925"(23.49mm), .610" (15.51mm) tall. Tone knob diameter at bottom .748"(23.82mm), .488" tall.