Comments about Det Mar Det Mar Tunnel Blower 4":
When it comes to a plain old 4" blower there doesn't seem to be many choices. I had to replace my ATTWOOD blower because it made a lot of noise. When I finally removed it, it was missing 2 blades on the fan. I read a few negative reviews on the ATTWOOD's (may not have meant much) but they were on back-order so I ordered the DETMAR. They all look the same to me and the prices on them aren't that different. I am happy with this purchase, but as far as any reliability, it hasn't been installed long enough.