The HiTechnic Touch Sensor Multiplexer enables you to connect up to four NXT Touch Sensors to a single NXT Intelligent Brick sensor port. The LEGO® MINDSTORMS® Education Software can read the state of each different touch sensor or the state of all of them with a single read command. The Touch Sensor Multiplexer Block is available for free download at www.LEGOeducation.us/hitechnic.