Solar power, plus a built-in dynamo that turns human-power into electricity, is what keeps this radio working when you need it. Just choose your energy source, power up, and turn it on. With the solar panel you can charge the internal Ni-Cad battery to run for 12 hours on a full charge. One minute of hand cranking (approx. 100-120 times) will provide 15 minutes of AM/FM play time (keeping the volume low can extend radio time to 20 to 30 minutes). Additionally the AC/DC adaptor allows you the convenience of plugging in when possible. And just in case you need backup power, the Solar Radio will also run on two AA batteries. Using the siren feature on our radio is as easy as setting the switch to "Siren" and turning the volume to "ON." Our Dynamo Solar Radio keeps you at the ready at all times with an AM/FM radio, a flashlight and an emergency siren - all in one! So whether you're caught in bad weather, at the weekend cabin, or packing your car's roadside emergency kit, it's great to have this multi-purpose radio on hand. China.