【Door Chime When Door Opens】Do you have a toddler who keeps sneak out of the bedroom? An elderly loved one with dementia or a pet try to leave the house? This door alarm when opened will alert you instantly with a chime, making it easy to monitor your home's safety. 【Door Chime for Business When Entering】This business door entry chime is perfect as a customer alert system for retail stores, offices, and warehouses. It rings the moment a customer walks in or someone passes by，so you'll never miss a single customer or visitor. 【Long Ring & Short Ring Modes】The long ring mode keeps ringing continuously, great for noisy places or scaring off intruders, so you'll never miss a door open alarm. When you want things quieter, just switch to short ring mode for a quick heads-up without the noise. Flip between them anytime you like. 【20 Chimes & Silent to 110dB】The wireless door chime for business or home has 20 chimes, 5 volume levels. With LED indicator keeps alerts visible even in silent mode. Tailor your notifications exactly how you want them. 【Easy Installation】The door sensor chime and receiver come pre-paired and ready to use right out of the box. No tools required. Simply plug the receiver into a standard outlet, peel off the adhesive backing on the sensor, and stick it onto any door or window. 【Long Range & Expandable】The door chime sensor has an 800ft operating range, reaching every corner of your home or business. Each door open chime can be paired with as many sensors as you need, and you can assign a different chime to each one, so you'll always know exactly which door or window was opened. Do you want to protect the security of your home? Do you still worried about the elderly and children sneaking out of home? Do you want to run your store more efficiently? What are you waiting for? Don't hesitate, Daytech door chime is a good choice for you. It is made of high quality ABS material, more robust and durable. this door chime has been tested tens of thousands of times for longer life. With a working distance of 1000 feet, you won't miss a single doorbell alert. Protect your home security at all times. How to change the ringtone: Step 1:Press the " forward " / " backward " button on the receiver to choose your favorite melody. Step 2:Press and hold down the volume button ,until it makes a "Ding" sound and the receiver indicator flashes. Step 3:Separate the sensor quickly,it will makes a "Ding-Ding" sound and the receiver indicator flashes. Step 4:Separate the sensor again to confirm whether the current ringtone is the one you have set,if yes,the pairing is completed. How to pair more transmitters: Step 1:Press and hold down the volume button on the receiver until it makes a "Ding" sound and the receiver indicator flashes. Step 2:Separate the sensor quickly,it will makes a "Ding-Ding" sound and the receiver indicator flashes. Step 3:Separate the sensor again to confirm whether the receiver can sound,if yes,the pairing is completed. If the receiver can not work when you receive it, please pair it to the sensors. Specifications： Working voltage of Receiver: 110-260V Transmitter Battery:3V 23A Alkaline battery Volume range: 0 to 110dB Range: 1000ft (in an open area) Operating Temperature: -2F to 158°F /-18°C to 70°C Package door chime set Double Sided Adhesive Tape 12V 23A Battery User Manual Notice:The installation gap between 2 parts of the magnetic sensors should be less than