Frequency:433Mhz Learning code matching chime and transmitter to avoid interfference. Numerouse receiver can match with Numerouse transmitter. Batteryless kinetic transmitter 150m in open air. Volume can be adjusted on the receiver.4 volume (from 25-110dB) 52 melodies can be chosen. America, British,Europe,Chinese plug can be chosen.
ADD:25th Road ,Wenzhou Economic development zone,Zhejiang,China.