Vapor Filter for Vacuum Pump

I recently purchased a Robinair 15800 VacuMaster 8-CFM Two-Stage Vacuum Pump. While it includes a rudimentary filter to catch the compressor vapor, it still generated quite a cloud--which made it unsuitable for indoor use. So I made this Thing, which allows two 3M respirator filters to be fitted to the vent hole on the pump. It eliminates all visible vapor, and presumably more based on the specs of the 3M filters.