CWDM is a low-cost WDM transmission technology for MAN Network, which uses the huge bandwidth of single-mode fiber in low-loss region to couple different wavelengths of light to one fiber for transmission. The protocol and rate of cwdm are transparent and support 1G/10G Ethernet, SDH/SONET and 8/4/2/1g fiber channel on the same fiber link. We offers WDM products with a very high level of protection, not only using high-quality shell materials, rust-proof and wear-resistant, and the product itself conforms to industry standards, with very good stability and reliability, low insertion loss and excellent channel isolation. At present, CWDM technology has been widely used in telecommunication, broadcasting, enterprise network, campus network and so on.