Pinion Bearing for Mercury, Mercruiser, OMC, Johnson, Evinrude. Replaces Mercury or Mercruiser 31-42647A1 and OMC Johnson Evinrude 387817. It is designed for the following Mercury V6 outboard applications but may fit more: 135 HP and 150 SN A904646 and up, 175 HP SN 6618751 and up, 200 HP SN 6625221 and up, 220 HP SN B117316 and up, 225 HP SN D280813 and up. Also fits most Mercruiser Alpha One and Gen II lower gearcases. Also fits most Johnson / Evinrude gearcases from 140HP - 235HP. Also fits most OMC 400 & 800 Series Stringer Gearcases.