Saab / Bosch BOV / by-pass valve.  This unit is from a recent crash damaged 2004 Saab 9-5.  Pressure tested, this is a GOOD USED unit.  Guaranteed to work properly, and I will also give a 30 day warranty.   These units can vent directly to the atmosphere, (they are loud like this) - or can be used to recirculate, as they are installed from the factory - in which case they are almost silent assuming they don't dump back in near an open air intake.

 Original part number 0 280 142 110    /  0 280 142 103

These units are typically dead reliable in Saabs (which run a bit.... conservative, boost from the factory) - higher boost?  They hold just fine till about 25 PSI, with reasonable reliability.  Great for a replacement unit in Saabs, VW's Audis, Hondas, etc etc.  Your choice.  You probably won't find one of these cheaper, for an aftermarket unit!  This is OEM manufacturer BOSCH quality.  These are GOOD units.  Yes, it's used.  But I bet you get years and years of life out if it.