This is a top burner knob that is used on oven ranges that were manufactured prior to 2003. A burner knob is what the user turns to adjust the temperature on the burner. This part is manufactured out of a black plastic material and has white lettering on it.A new top burner knob may be needed if the original is cracked, broken, or damaged in any way. If any of the letters wear off of the knob, the user may wish to replace it. If the back of the knob is stripped out and it just spins without activating the range, then it will need to be replaced.This top burner knob is a genuine Viking part and is an OEM part sourced directly from the manufacturer. It is sold individually. This particular top burner knob is compatible with oven ranges that are manufactured by the Viking brand.