PIR TechnologyThe detection range of the infrared sensor is about 4-8m (13-26ft) and the maximum working range is 280m (918ft). You can place the infrared sensor detector at the entrance, porch, gallery, mailbox, and place the receiver in your home. It will detect movement and send a wireless signal to the receiver, so you can always understand the situation and ensure safety. 5 Modes to ChooseThe 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 the doorbell mode to meet your needs. There are up to 113dB alarms in the alarm mode, which effectively helps to prevent intruders. Colored light / night light mode is silent, 4 levels of brightness and color are selectable, very suitable for people with hearing impairment or sleeping babies at home. Easy to InstallThe device can be charged USB or installed with batteries to make it work better . Both the infrared sensor and the receiver have a mounting base. The infrared sensor can rotate 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. More ExpansionEach receiver of the motion sensor detection alarm can be used with up to 32 motion sensors. The number of transmitters and receivers can be selected arbitrarily, can be freely matched and special lights or ringtones can be set to each other. [Multi-function Motion Sensor] widly range of applications. It can be used as a doorbell, caregiver pager, anti-theft alarm, pet monitor, mailbox alarm, store welcome doorbell, it can be successfully used in your home, hotel , Hotels, offices, warehouses, office buildings, etc.