Made of high quality ABS Plastic shell. Inner is 40ah 3.6v MH which could be chargered in sun light, and 3led based on 5mm diameter. In strong sun light, 5 hours can be powered, and you can use 2 hours continuously. The life of the solar is 5 years. And compass on the back to ensure you arrive the correct destination when camping. Attach to a keychain, backpack, fishing gear, hiking gear, and many other uses.