Though you can really do the same thing by buying a few line-level thermostats and motorized dampers, separately instead of depending on their expensive and advanced multi-zone thermostat systems that are part of the kit.
The high-tech pneumatic retrofit options might be easier to install (and therefore worth the extra expense) in some situations:
http://www.amazon.com/Vent-Miser-91667-BR-Programmable-Energy-6-Inches/dp/B000WAA8XM/
For the basic (manually adjusted) dampers, you can see the first segment of this video:
https://www.youtube.com/watch?v=u8jM9z3scQk
And the last 5 minutes of this one:
https://youtu.be/UPbjM08DGZY?t=18m23s
For an automatic zoning retrofit, it's easiest to find one of the forced-air zoning retrofit kits like the Honeywell TrueZone:
https://www.youtube.com/watch?v=5G7ZOsNGBJU
Though you can really do the same thing by buying a few line-level thermostats and motorized dampers, separately instead of depending on their expensive and advanced multi-zone thermostat systems that are part of the kit.
The high-tech pneumatic retrofit options might be easier to install (and therefore worth the extra expense) in some situations:
https://www.youtube.com/watch?v=F2EJLhZ939A
http://www.retrozone.com/Catalog/retrofit.htm
Well, at least that should be enough to get you started.