... power supply: 2pcs button cell inside, hand-pressing flashlight GB1003A 1. LED hand pressing flashlight, mini LED flashlight, LED, dynamo LED flashlight ... . power supply: 2pcs button cell inside, generating electricity by hand pressing,3. 2 LED lights4. lifespan of LED: more than 100 ... . size of unit: 11*5.5*4.4cm6. Attached with a string, easy to carry.