One hundred percent organic, self heating, and self recharging. Batteries not needed. Self feeding, but I wouldn't recommend using this option. They vibrate, making a soft soothing sound, with a built in sensor to automatically turn off once you fall asleep. Molded to perfectly fit the contours of your body, they are adjustable to your needs. Also self cleaning with a neat disposable waste system. Best of all, no moving! By morning, they have mysteriously been relocated into another part of the house, most likely found re-warming in a sunbeam.Warning: Do not wash. Do not dry clean.