For those that might be interested I just had to replace the impeller in my new Onan Cummins 7.5KW MDKBJ. The part number listed is 132-0493, however the only part the marina had was 541-1524. It was an exact match. It's possible they are the same part. In looking at the original I removed and the 541-1524, they are actually Sherwood 8000K Impellers, it's molded right into the rubber. As you can imagine the Sherwood part on the open market is nearly a 1/4 of the price of the Onan Cummins packaged part. Buying an OEM replacement for my Yanmar 4JH5E is actually very affordable by comparison.