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 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.