Originally Posted by martix_agent
The reason is that a lot of people have both a poppet and a spool valve marker. This elimiates a HUGE cost, and means you only need one marker (and for a minimal fee, you can swap between valves)
Did you see the cost of this marker?
Anyways, neat Rube Goldberg modular valve.
Feels like there's a new variation of the Ion every year.