Product Detail Up to 30F cooler. *best used in hot and dry environments. Runs on 4x batteries or USB power (adapter included). Adjustable speed control. 30db whisper-soft turbine system. 90 degree vertical airflow control. Produces a 15 knots sensational breeze *measured at outlet vent. . The "Handy Cooler - First-ever Evaporative Cooling Mini Fan / Battery Fan / Small Desk Fan - BLUE" is best product for you. We recommended Handy Cooler - First-ever Evaporative Cooling Mini Fan / Battery Fan / Small Desk Fan - BLUE