This versatile USB fan integrates the desk top and clip designs, suitable for various places, great for office desk, baby stroller, car backseat, bicycle, camping tent, home, kitchen, dormitory, library, gym exercising, outdoors/indoors activities, also an ideal gift for friends, colleagues and family members. No extra batteries are required. 4~ 27 hours working time depends on different speeds. It can work up to 27 hours on minimum wind(1200rpm), 13 hours on natural wind (1500rpm), 6.5 hours on normal wind (1900rpm), 4 hours on maximum wind (2200rpm) after fully charged. MT-L007F clip on fan is definitely your best choice. Adopts 5pcs bionic fan blades and brushless motor, strong wind while the volume just up to 40 decibels, allowing you not being disturbed even turning on the high-level wind; detachable fan hood degisn makes the cleanness of the fan a piece of cake. So enjoy your fresh and natural cool breeze anytime, anywhere. No matter it is placed flat on the table or clamped, it will not slip. By repeatedly pressing the power button on the fan body to control the on/off and speed levels of the fan. Curvilinear form narrow gap design protects the baby's fingers from injury. After long-time use, the fan blades may collect dust, you can easily open the frame anticlockwise and clean it with dry material.