Yanmar 3YM20 Belt 129612-42290 (Aftermarket)
Belt suits Yanmar marine engines:
2YM15, 3YM20
Also for 3YM30 - Belt (Hitachi 60A & 80A Alternator Eng S# up to E20547 )
Can be used in place of 119831-42290 ( 37.5)
This is a non-OEM, aftermarket part REC 129612-42290E