High Country used to sell bows (the SSR line)equippedwith what was called a Perf-X cam. It was a one-cam system, but it was really a pretty cool setup:
The Perf-X cam was adjustable from 45 - 80#, and draw length could go from 25-32". All without changing modules or limbs.
The bows looked like tinkertoys, but they shoot really well. I think most of them barely weigh in at 3#.
It really was a nice setup, b/c you could essentially buy the bow, then give it to a 45#, 26" draw youth hunter without changing a thing. Then, as his draw length/weight increased, the bow could grow with him without buying new cams/modules/limbs.
One of those really great ideas that just slipped through the cracks and never caught on.