I needed to replace the blower on my Travis Industries / Lopi Freedom Bay fireplace insert. They don't sell parts and wanted over $400 for a whole blower assembly. After lots of searching I found that the K612 with 6038 and 6039 blower wheels would fit. They are working great so far. Time will tell on the motor longevity, but so far I'm pleased.
I used these to replace the plastic blower wheels a Lopi Freedom Bay fireplace insert. They worked great and move more air than the plastic ones did. The job required 2 FASCO 1-6039 and 2 FASCO 1-6038.