This fully functioning camp stove uses excess heat to charge most USB chargeable devices. This camping stove gives a solid 60 minutes of talk time after 20 minutes of charging, and it can also boil 1 liter of water in as little as 4 min. 30 sec. CampStove weighs about 2 lbs. and is about the same size as a 1-liter Nalgene water bottle.