5 volumes and 36 ringtones Four different melodies such as agreements, jazz, folk music, etc. The volume can be adjusted from 0 dB to 110 dB. You can define different ringtones for each receiver of each transmitter. Long litter can reach a maximum external range of 300 m. In addition, the device can also be used as aid for care for the elderly or patients. IP55 waterproofing: the transmitter is protected against splashes, which guarantees optimal use outside Practical and fast: The receiver can be easily connected to the socket. When someone is at the door, press the button (the transmitter flashes in blue), the bell rings and the blue light flashes to warn you visually (good for hearing impaired). Each receiver can define a different ringtone. Easy installation: The button can be fixed to the door frame with screws or double -sided adhesive tape. The receiver is connected directly to the power source which must hear the sound, and the transmitter contains an integrated battery (the