Akari 4" Rechargeable Portafan (ARF-F013) Adjustable Height Micro USB Charging Foldable High Fan Speed Replaceable Battery Input Voltage 5Vdc SPECIFICATIONS: Battery Specs: 3.7V 1500mAh 18650 Lithium Ion Battery Input Voltage: 5Vdc Modes: 3 Speeds Charging Port: Micro USB Cable Charging Time: 4 hours Power: 2.5W