A vernier dial control knob will provide smooth and precise tuning for either a potentiometer or variable capacitor. Planetary drive provides 8 to 1 ratio, allowing for very fine adjustment of standard controls. The metal dial plat is calibrated by etching and paint filling on brushed satin finish for a very attractive appearance. Knob is calibrated over 180 degrees of turn, reading from zero to 100 by clockwise rotation. Fits standard 1/4" control shafts and mounts on surface of cabinet or chassis. Very useful with any circuit where fine tuning is required. Diameter 1-1/2". Calibration: 0 to 100