PIR Technology: The detection range of the infrared sensor is about 4-8m, and the maximum operating range is 280m. You can place the infrared sensor detector at the entrance, porch, porch, mailbox, and place the receiver in your home. It detects motion and sends a wireless signal to the receiver, so you can always understand the situation and ensure safety. 5 modes to choose from: The receiver has welcome, alarm, doorbell, color light and night light modes . 5 welcome languages can be selected in welcome mode. There are 36 ringtones in doorbell mode to meet your needs. There are up to 113dB of alarms in alarm mode, which effectively helps prevent intruders. Colored light/night light mode is quiet, 4 levels of brightness and color are selectable, very suitable for hearing impaired or sleeping babies at home. Easy to install: the device can be USB charged or installed with batteries for better operation. Both the infrared sensor and the receiver have a mounting base. The infrared sensor can be rotated 360 degrees left and right, and 180 degrees up and down. It is very easy to install and can be rotated to any position you need. -8