Just google enderle fuel injection, they have breakdowns of the parts, they use a different type of barrel valve, uses the same pills, but some of the other parts have different ways they function, Just like Kinsler, they use a pill, in all their bypasses, where Hilborn doesn't, to me, it just makes tuning more complicated, because you have a pressure setting, and a pill size change to make in each one, except the main, even in the hi-speed adjustable, they have a pill in it. Bob