It would have to be a Classic III head because the Classic 1CR and Omega !CB does not have the Visi Belt window in the middle of the Belt Lifter. If you removed the Belt Lifter from a Classic or Omega head the hole in the center is much smaller. It must have been a factory flaw that there was no holes for the Shag King, in all the years that I was a Kirby Area Distributer, I have never seen a head like this.