Compatible with the following engine models (and the boats that we are aware used these engines... There could be other combinations as well):
• 5411 (Catalina 27, Catalina 30)
• M-12 (Catalina 25, Capri 26)
• M2-12 (Catalina 25, Capri 26)
• M-18 (Catalina 27, Catalina 30)
• M3-20 (Catalina 27, Catalina 28, Catalina 30)
• M-25 (Catalina 30, Catalina 34, Catalina 36)
• M-25XP (Catalina 28, Catalina 30, Catalina 34, Catalina 36)

• Outside diameter: 121mm (about 4-3/4")
• Hole details: 24 total holes on 111mm (about 4-3/8") diameter circle
• Small holes: 16, 5mm (about 3/16")
• Large holes: 8, 6mm (about 15/64")
• Hub length: 23mm (about 1")
• Number of springs: 6, all the same size

1) If your boat has a 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.