The PI31-PS Powered Whiteboard Array Speaker from Califone features a 25W three 3" powered speaker. This array speaker technology focuses the sound pattern more directly at the audience with a narrower dispersion angle. This makes for a clearer and more evenly balanced message by not bouncing its sound off walls, so it doesn't contribute to existing ambient noise levels. A single 3.5mm audio input enables connecting audio source from smartphones. The PI31-PS provides fixed & variable line level outputs for adding speakers and other connected capabilities.