The EMP Generator produces a high-frequency electromagnetic waves field. An energy-saving lamp around the generator induces electromagnetic waves and generates an electric current. When the electric energy is sufficient, the lightbulb will light up. It can also be used to check the quality of fingerprint locks. Features: Compact size for easy carrying and operation. It can be used to check the quality of lightbulbs or fingerprint locks. Plug-in emitting heads, triode can switch by yourself. High frequency power, fine effect, more stable. Two gears for a strong effect. The coil can be adjusted by yourself. If the coil is reduced, the power will be reduced, otherwise, the power will be increased. Specifications: Plug: US-plug Main color: black Material: plasticsandmetal Battery: 3.7V, 250mAh Host size: 80 x 43 x 24mm or 3.1 x 1.7 x 0.9in Package size: 150 x 102 x 40mm or 5.9 x 4.0 x 1.6in Package weight: 192g or 6.8ounce Packing List: 1 x Electromagnetic Pulse Generator 1 x Plug 1 x User Manual 2 x Coil 1 x Metal Needle 1 x Triode