Built to specifications as per Auto Speed website articles:

Part 1: http://f2.autospeed.com/cms/A_0670/article.html?popularArticle
Part 2: http://f2.autospeed.com/cms/A_0685/article.html

It consists of a pressure regulator, relief valve, and one way valve.  I have been frustrated in setting up other brands of bleed valves on my car in the past, with slow response and boost spikes. This works extremely well.

Regulator - sets boost level.
Relief valve - sets how fast/hard the boost level will be reached.

$150