avantek db-21 waterproof wireless doorbell operating at over 1300 feet, 2 remote buttons can have different tones, 52 melodies, cd quality sound and led flash avantek with superior performance and ultra-low power consumption, the avantek db-21 wireless doorbell stands out among rivals. it is the easiest and most convenient choice for homes, office buildings, hotels and more. <br> <br> <b>long operating distance</b> <br> <br>the doorbell supports an extensive 1,312-ft working range (depending on the operating environment). rest assured that you’ll never miss any important guests or urgent deliveries again with the help of this doorbell. <br> <br> <b>durable and waterproof transmitter</b> <br> <br>the built-in 230 mah cr2032 lithium battery has an ultra long three-year lifespan, saving you the annoyance of frequent purchases and replacements. the impressive ip55 dustproof and waterproof rating makes the transmitter tough enough to withstand various outdoor environments. and with a working temperature ranging from -4 °f to 140 °f, the transmitter can work for you in even the harshest weather conditions. <br> <br> <b>music to your ears</b> <br> <br>a wide selection of 52 melodies allows you to easily choose one to suit your preferences - enough for a new tune every week of the year, so you will never get bored with your doorbell’s chimes again. it is easy and simple to choose your favorite melody with the use of the next and previous buttons. you can also set a different ring tone for each transmitter, so you will know exactly which doorbell has been rung. in addition, the built-in 40 mm stereo speaker delivers clear and well-balanced sounds. <br> <br> <b>innovative memory function</b> <br> <br>one of the great advantages of the avantek doorbell is its memory function. every time you turn on the device after a power outage, it remembers your last-set melody and volume level. this makes it not only extremely convenient, but also very user-friendly. <br> <br> <b>note: metal will interfere with the signal and shorten the transmission range. please place the transmitter in areas away from metals.</b>