Desktop Light Show -- The popular plasma ball is now making a PC appearance. -- Simply plug this small phenomenon into your computer's USB port and watch in amazement as the electricity follows your finger tips while they graze across its surface. -- The 3" glass ball is compact enough to fit on any desk and offers a fun light show....and distraction from whatever spreadsheet or PowerPoint you've been working on. Works and looks just as good as bigger models for far less money and no batteries to replace!