There was a point when IVS still used Fragramatics hulls, but they built their own internals run by a PLC, and it was a piece of crap. It had a double or triple peristaltic pump in the dome and solenoids that would close for each function to stop pump bypass. They used some cheap pump that would crack and leak, and the liquid would run through a weephole and right into the PLC and other electrical in the front. Yes, there's a pump on the fragrance units too, they bragged that it moved much more chemical than a Fragramatics unit. A guy I know bought the first batch of these and probably spend $5000 on six units just getting them to work. Avoid.