The following sensing method included in the E3Z series is the limited reflective. It is similar to diffuse reflective as it is single housing, requiring no additional parts and it also uses the object reflectance for detection. However, the sensing range for this sensor is better described as a sensing window. Only able to sense objects between 30 mm (±20 mm). The sensing window can not be changed as it is determined physically by the construction of the sensor. This sensor is used in applications at very short ranges and can detect smaller height changes by determining whether or not the object is in the window of detection or not such as bottle cap presence/absence as well as clear object detection.