Motion detects with Ease: A motion alarm is essential for caregiver. The Motion Sensor and Pager allows the caregiver freedom to monitor the slightest of movement remotely. Wireless Sensor detector: This motion sensor operates on batteries or USB power.This pager operates on batteries. The pager can be carried by the caregiver inside a pocket or put on a plat serface. The sensor is placed along the bedside of the person with special needs. While the person moves, the sensor will alert the caregiver in no time. Motion Sensor: The motion sensor activates when movement occurs within 16.4ft range x 110°. This transmits a signal to the receiver and alerts you with a ringtone every time the sensor is activated by motion. Wireless Portable Receiver: The put 3*AAA into the receiver. Unique Ringtones with Volume Level: You can personalize your doorbell with 58 unique ringtones and 5 volume levels. Easy to Install: Wire free and easy to install. Versatility: Each receiver can be paired with up to 20 transmitters, and each transmitter can be paired with up to 20 receivers. Packing List: Receiver *1 Motion Sensor *1 AAA battery *5