Out standing addition to your favorite guitar, A real head turner . Mercury dime  with aluminum sides and a small footprint. 5/8" at the bottom and 3/4" high. They fit a 6 mm split knurled potentiometer shaft and I Can also adapt them to fit a 1/4" smooth shaft with a set screw, just leave a note . I hand make all my guitar knobs  here in the USA. Please check my feedback and buy with confidence