Looks to be a Forge BOV(or a good knockoff of it). Forge makes great stuff, I use their products on damn near every turbocharged car here.
This is the BOV I had on my 965 before I sold the car last year. Fully adjustable and adaptable to any fitment necessary. I now have two of these for my current project

And yes, that's a quarter right below the BOV.....one of these valves will flow as much as two of the smaller Forge units, but requires some custom-fabbed intercooler/charge piping work to make it fit properly(doesn't come close to fitting stock location)