52 SONG, 4 VOLUME LEVELS: This wireless doorbell has 52 melodic ringtones from around the world that can be changed with a simple press of a button. The product has four adjustable volumes (including silent mode), and also has a blue flash, and the silent flash mode is always on to meet your different needs. 400 Meters Range: Wireless signals can be transmitted within an ultra-long range of 400 meters (in open areas, the signal has good wall penetration capabilities, the signal can completely cover your home without interfering with other devices). . Memory function: This wireless doorbell will automatically save the ringtone and volume you set, and will automatically restart after an unexpected power failure or when it is turned on again after being unplugged, eliminating the need to reset it to your preference. Waterproof and dustproof: It has IP44 waterproof and dustproof function, which can ensure the normal use of the wireless doorbell outdoors. The operating temperature range is