Compatible with the following engine models (and the boats that we are aware used these engines... There could be other combinations as well:
• M-25XPB (Catalina 28 MkII, Catalina 30 MkIII, Catalina 310)
• M-35B (Catalina 34 MkII, Catalina 350, Catalina 36 MkII)

• Outside diameter: 157.2mm (about 6.189")
• Hole details: (5) 6.53mm (about 0.257") holes on 142.06mm (about 5.593") diameter circle
• Hub length: 30mm (about 1.181")

1) If your boat has an different engine, call our Tech Support line to get information on the appropriate damper plate for your engine as the hole pattern is different.

2) The pricing of the aftermarket and the OEM versions both may change with each purchase. Both are sourced from overseas factories and are competitively priced each shipment by the importer.