The Kendrick 2001-FL Firelite Camera Cozy Package for Large DSLR Cameras, which comes with the MICRO FireLite Controller, a camera lens heater (for lenses up to 3" in diameter) and the DSLR Body Sock. It is an excellent, inexpensive, lightweight solution to dew prevention, frost prevention and electronic cold weather operation for anyone doing outdoor photography with a DSLR Camera. The loose fitting sock, which is anchored over the camera lens, can be easily lifted over the camera body to give access to the LCD Display, buttons, plugs and camera controls. A MICRO controller setting of 100%, a 6 amp hour 12 volt battery will give about 9 hours of continuous operation before the battery will need recharging. A 3 amp hour battery would give about 5 hours of operation. Typically though, a 50% controller setting is more realistic, even in cold weather.