This is a top quality oil breather box for your performance VW engine.  Generally, the breather hoses from your crankcase and valve covers are plumbed to this box, which contains a high quality foam to remove the oil mist from the crankcase fumes, where it can be collected and drained back into your engine.  It is a TIG-welded polished aluminum box that has an easily removable vented lid, held in place with a standard Dzus fastener.  The fittings are the standard #8 (-8 AN) to secure your hoses to.  It holds approximately 1.5 quarts.  It measures 10-3/4" x 6" x 2-1/4" overall, including mounting brackets and fittings.