This is a genuine Novarossi brand roto start system for the Novarossi .28 series of pull-start engines (528XRP 8-port and 528XSP 3-port). This rotostart assembly replaces the pull start assembly and allows the engine to be started with a regular 1/4" drill attachment and a standard power drill.
Note: This roto start requires a FMS22807 one-way bearing. This bearing is standard in 2006 and newer 528XRP and 528XSP rotostart, or pullstart engines. To determine if you have the correct one-way bearing measure the shaft that goes into the one-way bearing if it measures 8mm you have the correct bearing, if the shaft is smaller than 8mm you will need to purchase a NVR22807 one-way bearing to match the new roto start.