WIRELESS MULTI CHANNEL INTERCOM SYSTEMS UP TO 16 STATIONS : You can dial and communicate between all extensions up to 16 intercoms. Each of the intercoms have two digits number like 11, 12, 13 etc. For using lift hand set, hear the dial tone and then dial required intercom number, then dialed intercom will ring and you can hear the ring back tone, when the person lift the hand set, you can communicate. All intercoms are using different frequency and deferent security code with frequency multiplexing technology. So you can communicate 8 pairs at a time without overhearing or mingling. Also transfer telephone call with dialing facility (optional). Range up to 200M without any cabling on same electrical phase, range up to 2KM on separate single pair parallel cabling. This advanced unique wireless intercom system from THODUKONICS which is 15 years experienced company . we are not a dealer, we are manufacturer! Purchase directly from manufacture. Product Features: Full duplex communication like a telephone. (No "Push and Talk" ) Intercoms expandable up to 16 numbers (16 stations) Cordless Operation (Electric power line communication) Easy Installation (Just plug and talk, no wiring) Works on 90~240VAC Power Line (in Same Electric Transformer) Digital Frequency multiplexing Technology Different channel and Different Security code (complete secrecy) High quality electronics circuit (long lasting) Loud and pleasant Ringing Original Ring back tone (no duplicate ring back tone) Both party ring cut off system Third party calling indication Simple Operation (Just plug and talk) Light weight Handset One year Warranty No Mechanical switch (hook switch) More details Please visit oue web thodukonics or MSN thodukonics