The incredible Pocket Plasma Clip-On uses super bright technology combined with miniature electronics to create a flat panel disk with an amazing display of plasma light which will respond to your touch, voice or dance to your music. It's battery operated and portable, so you can clip it anywhere - wear it as a belt clip, attach it onto the sun visor in your car, clip it to a shirt pocket, or just take it to parties and watch people go nuts! The Pocket Plasma is just like its popular home-decor big brother, the Lumin Disk- now in a size you can take anywhere! Has a normal "on" mode as well as a sound-responsive mode that dances with the music or your voice. Requires 2 AAA batteries, not included. The integrated clip is similar to a pager or cell phone clip. The Pocket Plasma's flat panel is made of glass, with a plastic rear compartment. The panel is approximately 2.75" diameter (7 mm)and the entire unit has about 1.25" depth.