[Package Contents]: 1 receiver, 1 motion detector, 1 user manual, 1 receiver bracket and accessories for motion detector to install. They are only used indoor, please don't expose them to the sun or rain. [Powered By]: Both the receiver and motion detector can be powered by DC/5V power supply or they also can be powered by AAA batteries(Not included). The receiver need 3 AAA batteries(Not included), motion detector need 2 AAA batteries(Not included). [Memory Function]: This motion sensor alarm kit has strong memory function, even if a power outage, the ringtone and volume or the mode you set previously will not change. [Four Volume Level]: There are 4 levels adjustable volume for you to choose.You can switch the volume button to adjust the volume according to the needs of the scene. If you need mute mode, you can change the mode into Night Light Mode, this mode only LED light will be on, has no sound. [Four Modes]: This motion sensor kit has 4 modes---1.Welcome Mode---The receiver will emit "Hello, Welcome" sound.This mode has 2 type sounds, switch [Music] button can change the sound into "Hello, Welcome"in English. 2.Alarm Mode---The receiver will emit "Wu-Wu-Wu" sound about 15 seconds. 3.Doorbell Mode---There are 32 melodies, once the motion sensor detects movement, the receiver will sound the melody you select. 4.Night Light Mode---The LED light of the receiver will be on for 2 minutes.