Handheld Portable USB Cooler Fan & Mini-Air Conditioner Small fan cools air up to 30F. Runs on 4x batteries or USB power (adapter included). Adjustable analog speed control. 90 degree vertical airflow control. Flat bottom surfaces allows easy transformation from a hand held fan to a desk fan. 15 knots sensational breeze *measured at outlet vent. Simply add water to activate cooling feature