Features: 1) Its switch system is based on advanced magnetic induction technologies, so it has a long service life and reliable performance 2) Shaking it for 30 seconds, and it keeps working for 30 minutes. 3) No battery inside the flashlight 4) There is a big capacitor inside the flashlight.Its use is to keep power from shaking and supply power to flashlight. 4) Waterproof 5) Warranty: 1 year 6) Length: 17cm Inner packing: 1pc/color box Outer packing: exported carton Qty: 100pcs/carton Carton dimensions: 47x 26 x 40cm G.W.: 15kg