The Comet 200836 spacer is used between the clutch halves. It is used to fit a wider belt. Without the spacer, the Comet series 20 clutch fits a belt with 3/4" top width. Using one spacer ( 1/8" thick ), the clutch can use a 7/8" top width belt. This is a common adaptation to use the Comet 20 on trail scooters like Tote Gote.