Precision Pet K-9 Kooler www.petco.com - $11.99 Product Description: Cool your pet's cage or kennel for up to 100 hours on just two batteries. Powerful airflow. Runs on two D cells or a three-volt adapter (not included). Features two speed adjustment for high or low air flow. Retractable hooks hang fan on outside of any cage and then retract for storage. AC/DC adapter socket for use with any adapter. Machina's Review: I just picked this up for my ratties recently because of the raising temperatures, and they love it! I usually have it set on low most of the time and they enjoy sleeping by the gentle cool air flow. It's like having their own rattie a/c. It hangs off of the side of the cage so there is no way they can stick their little hands in there. The noise level is fairly low. I'd give it four paws.