The Corner Coach is the only adjustable / removable seat bump that allows users to fine-tune their desired riding position on the motorcycle's seat. Mini size fits factory seats 50-85cc. Installation: Remove seat bolts, and slide The Corner Coach over the seat to desired position (recommended rear 3/4 of seat). Pull the strap tight and tuck excess material under the seat base. Re-install the seat bolts. *Not designed to be permanently mounted. Use as needed.