The DSI Fan keeps your camera cool! Give your camera a boost by enhancing its air cooled properties. The fan fits DSI and DSI II Cameras. It has been designed to give enhanced air cooling to the camera. The fan will keep the camera up to 9 degrees Fahrenheit cooler than using the camera without a fan (5 degrees Celsius cooler). The fan comes equipped with a battery pack for simple in the field use (batteries not included). The fan will also work with the Meade 541 power supply. Keep your camera cool! Lower the cameras operating temp. by up to 9F (5C). Works with all Deep Sky Imager cameras. Runs on 8xAA batteries (not included).