The POWERplus Wolf is a high quality FM radio with a built in rechargeable battery that is recharged by either winding the strong crank handle or via the USB cable that is included in the pack. In addition to being a great radio, it is also a powerful torch and even has a built in SOS alarm. The built-in rechargeable battery powers both the radio and the flashlight. The Wolf even has a glow-in-the-dark identity ring making it easy to find in dark situations, making the POWERPlus Wolf the perfect tool to take camping or walking. A fantastic, high quality item for anyone spending some time outdoors. Main technical parameters: Battery: Ni-MH rechargeable 3.6V/80 mAh Operating time when fully charged: Radio 1 hour, Flashlight 2 hours, Personal alarm 20 minutes Reception scope of radio 76-108 MHz Sensitivity of FM > 10uV Loudness of personal alarm 80 dB