Microcontroller Based PBX System with 6 Extensions can store frequently used numbers in its memory. Microcontroller Based PBX System with 6 Extensions is manufactured by Matrix Telecom Private Limited which is an ISO 9001 accredited company. Matrix Telecom Private Limited also manufactures various types of cutting-edge telecom products like IP-PBX, universal gateways, VoIP gateways and terminals, GSM FCTs, GSM gateways, access control, time-attendance systems and fire alarm systems. The Microcontroller Based PBX System with 6 Extensions, Model Proton 206, is a compact communicator for homes and offices. This System is based on state-of-the-art surface mount technology [SMT] ensuring high reliability. This System has simultaneous ringing day/night modes and remote lock call transfer. This System has dimension of 26 X 28 X 7.5 cm and weight of 2Kg.