The EE-SX4009-P1 is a Transmissive Photomicrosensor with snap-in mounting. Photomicrosensor is a compact optical sensor that senses objects or object positions with an optical beam. 5mm wide groove, high resolution with a 0.5mm wide sensing aperture. Photo IC output signals directly connect with C-MOS and TTL. Connects to Tyco electronics AMP's EI-series connectors. The transmissive photomicrosensor incorporates an emitter and a transmissive that face each other, when an object is located in the sensing position between the emitter and the detector, the object intercepts the optical beam of the emitter, thus reducing the amount of optical energy reaching the detector.