Hi Mike.
This is the one that I installed to replace the white straight through one...
http://www.purewaterproducts.com/products/rc301
It is classified as a U-type ASV.
For some reason it gives 6 psi more pressure to the holding tank, which works better for the ice maker.
Got a 50 gpd membrane coming for the holding tank in the fish room. But that room won't be free until my son moves out... again!
Cheers,
T