[Updated Sep 14, 2015, see below]
There are two versions of this cooler, both works very well on my 2001 Wrangler:
RED - A bit larger on the outside as it holds the bottle in an angle to keep it away from the dashboard and the audio / navigation screen.
PURPLE - looks slimmer but has the same capacity, hold the bottle as close as possible to the dashboard and therefore may interfere when in front of a touch screen.
Personally I prefer the red version as it is not interfering with my touch screen.
The third part of the Red version is an optional bridge you need to glue in place in order to control the airflow and keep the bottle in the middle of the holder.
Apart from the four holes (for screws holding the container part) which only exists on the PURPLE version, the two Vent parts are identical.
Both versions can be used on center or side (window) vents. On center vents the holders are held with a latch preventing them from accidentally turning with vent’s bearing.
Sep 14, 2015 - Added a vent part that has a small bump to help "click" the part in the vent nozzle and prevent it from sliding out when driving off-road.
RED Bottle Cooler Part B - Vent with bump.stl