Description Mechanical seal and seat 12859-SHW assembly for Sherwood raw-water impeller pumps, used to maintain a reliable watertight seal and protect pump components in marine cooling service. Cross References/Supersedes: 12314, 12256 Applications: Fits selected Sherwood pump models G30-2B, G45-1, G7B, M71, G151, K75B, G21 and G9901/3. Construction: Carbon/ceramic mechanical seal and seat assembly for long service life in raw-water environments. Use: Replaces worn or leaking seal assemblies to restore proper pump sealing performance.