Roller Brush / Beater Bar Belt Dimensions: 12 13/16 x 1 3/4 (measuring from the outside tabs on either end of the brushroll) This is a replacement brushroll & belt is for the Dyson model vacuum cleaners which have a clutch system. The center of the brushroll is flat on two sides through the center as seen in the photo If you have the dial on your vacuum that allows you to turn off the brush roll for cleaning hard wood floors then this is the correct one for your vacuum. You can also refer to the measurements listed below. There is a difference in size between the two different types.