1). This flashlight DOESN"T need batteries or any other power supply. 2). With a mechanical electricity self-generating device inside, wind the crank of flashlight time and again and it will light up. 3). Easy to use at anytime, anywhere WITHOUT worrying about power supply. 4). Wind the crank of flashlight for 5 minutes and it will light for about 30 minutes. Lighting life: 10,000 hours. 5). When mobile phones are short of power, recharge mobile phones by connecting to the built-in output socket of the flashlight and wind for 5 minutes, and then mobile phones can work continuously for more than 10 minutes. 6). Safe, low noise and durable. 7). Small and pocket product size: 5 x 5 x 16 cm 8). A must-have item for travellers, explorers, hikers, family camping&picnic, and for those who often work in the field or open country. 9). Ideal as gifts or promotional/premium items for advertising, automobile, travel and many other industries. packing qty: 80 pcs/ctn meas: 47*35*36 cm N.W. : 16.7 kgs G.W. : 17.7 kgs