Motion sensors use three different kinds of technologies to detect movement: passive infrared(PIR) technology, ultrasonic technology and dual-tech technology which combines both PIR and ultrasonic technology. All three technologies have their pros and cons, while PIR motion sensors are still the most popular and widely used technology with significant advantages such as ultra-durable, being the most inexpensive, and low energy consumption. All Razyeek motion sensors use PIR motion sensors. For more discussion on these motion sensor technologies, read our definitive guide on occupancy sensors. Some other main features: Light Sensor/Daylight Sensing The light sensor or daylight sensing function allows a motion sensor to detect the ambient light with an integrated photocell. When the feature is enabled, the motion sensor will not turn on the light when there is enough natural light to save electricity in the daytime. Time Delay Time delay is the time that keeps the light on after no motion is being detected. This time window can keep the lighting consistent and prevent the motion sensor from falsely turning off the light due to a temporary motion-detecting failure. Sensor Sensitivity Sensor sensitivity is how far or how sensitive the motion sensor is able to detect a movement, especially a small motion. High sensitivity is not always good as it can be too sensitive, making the sensor to be able to detect people walking past the room which might falsely turn on the light when no one is in the room.