【Door chimes when door opens】This wireless door chime can be a good reminder for you if you have toddler who try to sneak out of their bed room or help alert you the elderly with dementia who is trying to get out of the house. [Wireless door chime for business when entering]: This door entry chime can be used as a doorbell for your retail shop for your commercial to remind you when someone walks into your store, you will never miss any customers(visitors) 【Easy to Install】The door sensor chime and receiver are paired already,Just plug the receiver into standard outlet, tear the double-side adhesive tape of the entry alert chime and stick them to any door or window. [26 Music with Mute to 110dB]: The door chime for business/home has 26 chimes with 5 adjustable volumes. With LED indicators and memory function: Keep the previous set tune after re-plugging it 【Long Range & Expandable】The door chime wireless door sensor has 500feets far enough to cover every door in your house or store. And each door opening chime for business can be paired unlimited magnetic sensor, you can also pair different ringtone to each sensor, so that you can realize exactly which door is triggered 【After-sales service】 Free return and exchange within 30 days, lifetime customer service. Any product issues can be contacted through the order, and we will solve them for you as soon as possible! UPC 682228238344 Brand SanJie Color 2 Sensors + 2 Receivers Voltage 120 Volts (AC) Unit Count 1.0 Count Item Weight 0.24 Kilograms Manufacturer SanJie Power Source AC Audible Noise 110 Decibels BuiltIn Media Adhesive tape, Product manual, Receiver, Screws, Sensor (battery included) Maximum Range 500 Feet Mounting Type Protruding Control Method Remote Item Type Name Door Chime Sensor Technology Contact Sensor Compatible Devices Smartphone Number of Batteries 2 12V batteries required. Manufacturer Warranty Description lifetime warranty