The On 3 Performance 50mm blow off valve has been sold now since 2007 and since day one provided us with a solid product.  Included with each kit is the blow off valve, flange, and banjo fitting.  We can supply the flange in either Aluminum or plated Steel so please specify when ordering in the notes.  This has been used on each of our turbo systems produced and ranging from 400rwhp cars all the way up to 1300rwhp vehicles.  Its a time provide part and works excellent without breaking the bank.