FUCTION:
camping or emergent light    
1)material:ABS OR PS                   
2)light source:  5 pcs LED                       
3)battery: 3  AA   1.2V 500mAH                        
4)solar panel:  4V   70mA                       
5)charging method:8 hours under the sunlight                               
6)discharging hours: 3-5 hours