This is a clock knob for an electric range, oven, or stove. It allows you to adjust the clock and cooking timer. No tools are required for this repair, the knob simply pops on and off the turn shaft. It is recommended to check all knobs on your appliance before ordering. This part is approximately 1/2 inch in diameter, is made of plastic,...Read more and is black in color. It is sold individually. This knob is a genuine original manufacturer part.