Interactive Pen - Blue (marked with blue on the side) is one of two interactive pens that can be used simultaneously with BrightLink 475Wi, 480i, 485Wi, 575Wi, 585Wi, 595Wi, 600 series, and BrightLink Pro series. To use simultaneously, the other pen must be Interactive Pen A - Orange (marked with orange on the side) Provides interactive drawing and mouse capabilities for BrightLink 475Wi, 480i, 485Wi, 575Wi, 585Wi, 595Wi, 600 series, and BrightLink Pro series interactive projectors Uses single AA battery On/off power button with sleep mode to prolong battery life 850nm IR frequency