MXR Style Fluted Knob (19mm)A better version with less paint chip.1/4" (6.4mm) smooth shaft pots12.5mm (1/2") tall19mm (3/4") at the skirtColor: BlackWith screwDimension: 20mm x 11.45mmPackage includes 1 pc per QTY ONLY!!!Best used for Guitar effects pedal knobs NON-KNURLEDFOR SOLID SHAFT ONLY..