Long Range – Operating range up to 1,000ft/300m in open area when there are no obstructions, ensures you to hear the bell and answer the door in time. Waterproof & Dustproof – Waterproof rating ensures the rain day usage perfectly. Sleek flat panel makes cleaning dust a piece of cake. Just rest assured to put it outside for convenience. 36 Different Ringtones & Adjustable Volume – The doorbell features 36 chimes and 4 level adjustable levels (25db to 85db) to suit your needs. Flashing light with audio alert indicators which is easy for people including the hearing impaired to notice. Easy to Install & Use – Easily plug receiver into an electrical outlet (no batteries required for main receiver). The push button can be fixed to the doorframe with the attached adhesive tapes. Simply mount the doorbell where needed and you are ready to go. Multi Use – It is fit for home, apartment, office, villas and more. You can use our doorbells to train dogs, using it to quiet down classrooms, seniors and disabled use doorbells as assisted living call pagers! Ensures that you will not miss any visitors, you can hear the sound even from back garden. A perfect use case scenario for these products: 1 Receiver&1 Push Button This item also can be used great for commercial space and offices. This item also works well for large homes or villas. This item also can be used as a simple alert device. A paging device for the elderly, can signal for care when they need it most. Specifications Wireless Range: 1000ft maximum in the open air Internal Sounds: 36 Chimes Volume: 4 level adjustable levels (25db to 85db) Transmitter Power: 1 × 12V 23A battery Note: Add on more receivers: Plug in the receiver. Press the volume button (the second button) of the receiver for 3 seconds and hold it, it enters the pairing mode. Then press the doorbell that you want to pair. After the pairing, lose the volume button.