BTOOP Rechargeable Battery Fan Stroller Clip on Fan with Three Speed Adjust 360 Degrees, Quietness (White, 5") This clip on fan is a rechargeable battery fan, which is suitable for any place in the summer, has features of portability, green energy, environmental friendly, low power consumption, strong wind power, rechargeable battery These mini usb fans are perfect for the kids. You can also use the mini desk fan no matter in the home, walking in the park, traveling outdoors, studying in the school, working or painting This battery powered fan use the removable battery structures make users more convenient to maintain or replace batteries to enhance endurance The advanced power management technology provides a variety of power supply, which can use USB directly or be battery-powered, which makes this small fan really easy to use This battery provides long life and strong power output, and it can use about 2-4-6 hours according different speed.When you use usb directly,it only has one speed