KooPower 4-Inch Portable USB Mini Fan - Rechargeable Battery Operated with 3 Speeds 3 speed settings; Lighter AND Quieter 25% quieter than similar models Battery Powered by rechargeable battery or use USB cable Portable mini Fan can be used on table or many other places for convenience Note: please remove insulation sheet between the electrode and the battery in the first use; When being charged, the fan cannot be adjustable which always stays the second speed. If you need to charge batteries, please do not use it when charging via USB Cable. Perfect fan for the office, home, dorm, study, library, games room