Simply add water or ice, USB powered or a Power Bank. Currently on sale @ £39.
Portable Air Conditioner, 900ML 4 in 1 USB Small Personal Evaporative Air Cooler with Spray Modes & 3 Speeds 7-Color LED, 90° Rotatable Mini Air Conditioner Fan with Timer, Room Cooler for Office
Min Air Cooler with Remote, 1000ml Small Air Conditioner, Humidifier, 2-8H Timer 7 Led Lights 3 Speeds 3 Mist Mode, USB Air Cooler Fan for Home Office Camping, Outdoor
Portable Air Conditioner, 3-in-1 Evaporative Air Cooler with 3 Speeds & 2 Mist Modes, 1000ml Mini AC Unit, USB Powered Small Cooling Fan with RGB Light & Timer for Bedroom Office Desk Car
Portable Air Conditioner, Personal Evaporative Air Cooler with Dual Tank, 2 Mist Modes, 3 Wind Speed, USB Powered Desk Cooling Fan with 7-Color Mood Lighting for Office/Bedroom
