Features: Electromagnetic emitter DIY kit, optional with/without casing. Loose parts require manual assembly. The bottom electromagnetic box design allows for easy battery replacement without the need to open the casing, making it aesthetically pleased and convenient. Upgraded package, fast launching speed, long ranged distance, and fast energy storage. Can be used for scientific experiments, boost circuit electronic science experiment production. Specifications: Material: PCB+ABS Type: Loose Part without Outer Casing, Loose Part with Outer Casing(optional) Size: about 94x87x47.7mm/3.7x3.43x1.88inch Name: HU064 Upgraded Set Working voltage: 3.0V Power supply method: 2pcs Number 5 batteries, DC3V (requires self provided batteries) Accumulated current: 50-65mA Emission current: 70-80mA PCB size: 85x78mm; 50x53mm Package Includes: 1pc Electromagnetic Emitter DIY Kit with/without Outer Casing note: Loose part, need to assembly yourself. Please allow 1-2cm errors due to manual measurement. Please allow for slight color differences due to different display resolution.