Vpx is proud to bring you a cutting edge new whey protein isolate called, spirofuse reverse osmosis or sro! this invention is whey protein isolate by reverse osmosis spirofuse filtration or sro. roughly 10 years ago vpx was the first company ever to release aceramic filtered whey protein isolate supplement called cross flow microfiltration. this created quite a stir in the supplement industry because until that time only whey protein concentrate (wpc) or low grade ion exchange wpi was available. as you can imagine, there have been significant improvements in whey protein technology over the past10 years.