1 1/4" Knob For 0.25" D Shaft, Half Moon Later Rival 1.5 & 2 Quart Models New replacement knob for the 2/1.5 quart Rival slow cooker, Mainstays 2 quart & others. Will not fit the older models or the larger models. Knob is 1 1/8" in diameter and fits on switches with the 1/4" half moon shaft, not the earlier split round shaft styles. Great replacement switch knob for some of the SC200SS slow cookers.