This is an original OEM PCM O-Ring FOR SHERWOOD RAW WATER PUMP - Not the Seawater Strainer.
For the Seawater Strainer O-Ring is ITEM 11805 CLICK HERE for 3/4 - 1/2"
For the Seawater Strainer O-Ring is ITEM 11803 CLICK HERE for 1" - 1-1/4" & 1-1/2" strainers
Impeller O-Ring For Sherwood RAW WATER PUMP; O-Ring Only