This is a complete plug n call wireless intercom system with 100 extension preset and precode units of numbers 0 to 99. Features: 1. No cables or wires need, just plug n call system. 2. No installation, no installation cost(Do it yourself) 3. Works with or without electricity, 24/7 operation supported with inbuilt battery during power failure. 4. 100 extension units of absolute voice clarity and 100% non interference. 5. 200 to 300 meters of interconnectivity between units. 6. Preset and precode numbers 0 to 99, buy as you need. 7. Ruggedly and smartly designed for both vertical and horizontal mounting. 8. 1 year of absolute warranty, standard and durability guaranteed 9. Ideal for homes, offices, hotels, schools, hospitals and any establishments.