Feature:1. Small Body But Amazing Energy: Small enough, but it has an astounding energy that turns the sound. Take your time to avoid the big vibrations of the arcing sound.2. Type B Features: This music has circuit protection design, will not damage the input device, can play better quality music than arc plasma speakers, can only play square wave music.3. Easy Operation: Bluetooth, no grounding, no sound cable connection, Type B is designed for square wave music, can only play square wave music, very good.4. Endless Fun: This music has the function of wireless transmission and speaker, which can ignite the gas tube and various bubbles. It's the perfect teaching tool to stimulate students' interest in science.5. Safe to Use: For Tesla musical coil is excellent, the arc can be touched at will, there is only a slight feeling and temperature, you don't have to worry about it. It makes a very cool collectible and gift.Specification:Item Type: Bluetooth Music Coil Mode for Tesla CoilMaterial: Acrylic, PCBThunderlight Length: Approx. 0-10cm / 0-3.94inPower: 0-120W.Package List:1 x for Tesla Coil1 x Discharge Needle2 x Neon Bulb1 x Power Cord1 x User Manual