Domestic about the development of the market for the first time, is in 1995-1997. The communication between the first manufacturer of guangdong, fujian and other regions, regard it as shenzhen, guangzhou to treasure, fujian zhenwei, etc. These manufacturers committed to professional in the production of building intercom products, manufacturers scale expands unceasingly, the product technology is increasingly mature, and began to realize the importance of real estate developers, start working with real estate developers and gradually grow.