Hi this is a replacement stove top knob designed for a 4 burner GE electric stove. In my case the old knob just pulls off of the post. The cutout in the back of the knob is 4.6mmX6.6mm and is pushed somewhat tightly over the post the old knob is pushed onto. I designed this because the words printed on the stove had worn off, as such each knob is embossed with which burner it is for. (Example Front right, Back Left).