The EE-SX1330 is an optical switch made by Omron. It is a Surface Mount Technology (SMT) part designed for transmissive type photo sensing with a 3mm slot. It has a phototransistor output. The switch detects a change in light levels when the slot is blocked by an object, and the on/off state is determined by the light levels received. The switching distance or amount of light blocked varies depending on the model and sensing range. Applications include position sensors, presence/absence detection in mechanical systems, presence detection of marked/unmarked surfaces, and angular detection.