DESC: Two key technologies separate the V400 Laser Cordless Mouse for Notebooks from the rest of the pack. First, the V400 is the first mouse to use a dual laser tracking engine. Developed jointly by Logitech and Philips Laser Sensors, the dual laser engine is based on Philips Twin-Eye™ Laser technology, using two lasers to detect microscopic surface variations. The result is all-terrain performance merged with pixel-precise tracking.