The TiAL® QR Blow Off Valve Bottom portion will allow you to re-fit a TiAL Q Blow Off Valve to be a recirculating blow off valve. This QR BOV bottom half fits right up to the top part of the Q without any modification. Simply unbolt your Q as if you were swapping springs and switch all the internals into this recirculating body. The spring pressure will remain the same as it was in the Q. The QR Bottom is set up to accept two different types of return fittings - 1" for Subaru/Bosch style BPV's, 1.14" GTR style and 1.50" for DSM/EVO style valves. You'll have the option to choose the size you need when ordering. Each piece is CNC-machined from 6061 aluminum alloy, just like the Q, and anodized to match perfectly, available in silver, black, red, blue, or purple to customize the BOV's presence in your engine bay. You'll never know it wasn't a TiAL® QR BOV from the start!