Long Range - The range of up to 300m in an open area without obstacles allows you to hear the bell and open the door in time. Waterproof and Dustproof - The waterproof rating ensures perfect use in rainy days. The slim flat panel makes it easy to clean dust. Just put it outside for your convenience. 38 Different Ringtones and Adjustable Volume - The doorbell offers 38 chimes and 3 adjustable levels (can be muted) (0-85dB) to meet your needs. Flashes with audible warning indicators that are easily recognized by the hearing impaired. Easy to Install and Use - Simply plug the receiver into an outlet (no battery required for the main receiver). The transmitter (after inserting the battery) can be attached to the door frame with adhesive tape. Simply insert the bell where you need it and you're ready to go. Multiple Uses - Suitable for homes, apartments, offices, villas, and more. With our doorbells, you can train dogs and quiet classrooms, while the elderly and disabled use the doorbells