ITEM NAME:Keyestudio Photo Interrupter Module Sensor for MEGA 2560 R3 Black Description: This sensor is composed of an infrared emitter on one upright and a shielded infrared detector on the other. By emitting a beam of infrared light from one upright to the other, the sensor can detect when an object passes Between the uprights, breaking the beam. Used for many applications including optical limit switches, pellet Dispensing, general object detection, etc. Gap width = 10mm Supply Voltage: 3.3V to 5V Specification: Material: FR-4 epoxy glass fiberboard Size: Approx. 3.4cm X 2cm X 1.3cm / 1.34x0.79x0.51inch Package Includes: 1 Piece of Photo Interrupter Module for Arduino.1 Piece of Photo Interrupter Module for Arduino. This sensor is composed of an infrared emitter on one upright and a shielded infrared detector on the other. By emitting a beam of infrared light from one upright to the other, the sensor can detect when an object passes.