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.I printed this with PLA on a MakerBot Replicator 2. I've included the source SketchUp file in case someone needs to modify the design for a different vacuum pump or printer. I printed it upside down, with the hole for the vacuum pump on the top. Supports were required, but they came off pretty easily. The seals are closed-cell foam from a hobby store. I ended up using two layers, but one might work if it's thick enough. The part simply pressure-fits over the top of the pump's vacuum vent.