Features: The music coil produces different tones according to different discharge frequencies, and the spark gaps arc can also jump with the music rhythm, insert and use. Bluetooth-compatible connection, no audional wire connection, you just need to tighten the discharge needle, lower the power and frequency, insert in the power supply, and you can see light flashing in front of you. It has wireless transmission and speaker functions, can light neon-lights, and can contact at will with slight feeling and temperature. Small body, high power, it can emit 10cm beautiful sound, you can also connect the mobile phone application, convert to the music devices, and let the light flashing arc enter the music. Great learning tool to spark students interest of science, physical teaching, nice birthday gift, holiday gift, new year present for your kid, families or friend. Specifications: Material: Metal Size: Approx. 106x106x61mm/4.17x4.17x2.40inch Power Supply: AC110-240V 50/60Hz Power: 0-120W Light Length: 0-10cm (adjustable by knob) Package Includes: 1x Music Coil note: Please allow 0-1cm error due to manual measurement, make sure you do not mind before you order. Please allow for slight color difference due to different monitor resolutions.