Includes 3 manually controlled heat settings; Each C-pack 1300B battery provides up to 13 hrs of warming. The C-pack 1700 B batteries provide up to 17 hrs of heat; Fitted with Bluetooth technology, you can now control heat settings via your smartphone, using the Thermic Heat Control App; The app provides increased adjustability, personalization, and battery life through accessing 10 different heat levels, motion control, and eco mode; C-Pack comes with a USB charger, (Wall charger not supplied); C-Pack batteries are suitable for use with Therm-ic Insoles Heat Flat, Heat 3D and Heat Kit range only