I have a cheap ebay unit on my Syclone, works fine. Paid like $28.00 It is externally adjustable. It was cheap & it works is all I can say.
Normally I do not buy cheap products,, just wanted to try it out.
Main thing to consider is, if you are going to run high boost, should look for a valve that is large enough to expel the extra pressure quickly & reliably.
Cant go wrong w/a name brand, but you need to make sure they are not knock offs. Do your research.
