Working principle: This product adopts the principle of generating power with hand cranking to charge its built-in 40 mAh/3.6V storage battery, the storage power then be used for lighting. It also combines with the function of compass. Functions of the product: 1. Cranking power for lighting 2. Compass Features of the product: 1. Cranking for power generation 2. Good cranking handle, Low Noise, high power generating efficiency 3. High brightness lighting: the Max brightness of 1 light can reach 20000 mcd 4. Convenient to use, never need change battery, cranking to recharge 5. With compass function 6. Unique design, lightweight size, convenient to carry 1. Lighting: A. The max. brightness of 1 LED: 20000 mcd; The max. Luminous flux of 1 LED: 1.8 lm B. 1 minute cranking for 20 minutes lighting with 1 LED on 2. Lifespan Switch: 10000 times LED: 100,000 hours Plastic part: 5 years Whole unit: 5 years use Instruction: Lighting: 1. Unlock the handle. Hold the unit and crank the handle by another hand at the speed of 3 circles per second for about 1 minute, push the switch forward to turn on the light. 2. Switch model: push forward to turn on the light, backward to turn it off. Size: 91 x 48 x 36mm Weight: 73.39g