Feature:1. 38 melodies and adjustable volume: The receiver has 38 ringtones to choose from. 3 adjustable volume levels, you can set the sound and quiet (voice: sound indicator silent: indicator). 2. Long-distance connection support: working range up to 230 feet (70 meters) between receiver and transmitter and infrared detection range up to 3-7 meters. 3. Function: It can alert guests, notice door opening, deter unwanted intruders, and even know when children have access to restricted areas. 4. Easy installation: The sensors can be installed or placed anywhere in the room to provide an intercom alarm system. 5. Wide application: ideal for domów, offices, garages, yards and shopping malls. It can also be used for front door, back door, garage and driveway. . Specification: Item Type: Motion Sensor Alarm Material: ABS Battery: Infrared detector requires 3 AAA batteries (without battery) Voltage: 110 - 240 V Infrared detection range: 3-7 meters Music: 38 music to choose from, music button side to adjust Volume: three levels of volume control (high, medium and low) side volume button for adjustment You can set the sound and silent (resonant: sound indicator silent: indicator) Operating Frequency: 433 MHZ Working distance: 70 meters . How to use:1. Prepare six AAA batteries and install them in two infrared detectors before use 2. The bell is plugged into an outlet and powered. When the infrared detector detects a person, the bell will pick up the signal sent by the infrared detector and send the bell. . Package List:1 x Doorbell2 x Infrared Detectors 4 x Bracket Accessories 4 x Screw 4 x Expansion Tube 1 xInstructions .