Description in English:
The DEM-220T/220R Bidirectional Fast Ethernet SFP Fiber Transceivers are external transceivers designed for insertion in SFP (Small Form-Factor Pluggable) slots of network devices for transmission and reception of data signals on the fiber cables. These transceivers provide the 100BASE-BX operation and physical compactness to deliver the speed, reliable long-distance data transfer, and deployment flexibility that today’s fiber networks require.
 Ideal for Long Distance Application
The DEM-220T/220R transceivers can be used to connect together switches, servers and fiber modules on a campus or metropolitan area network (MAN). Providing up to 20 km of fiber cable distance, these highly integrated transceivers offer low jitter performance for extended optical link support without any degradation in performance.
 Reliable Transmission
The DEM-220T/220R transceivers combine transmitting and receiving signals onto one fiber strand using two wavelengths. These transceivers are used in pair. At one end, one transceiver uses one wavelength to transmit and a second wavelength to receive. At the other end, the other transceiver flips that relationship. 
 Standard Compliance 
The DEM-220T/220R transceivers use standard simplex LC connectors for fiber cable connection. They conform to industry standards and are interoperable with certain D-Link switches. Hot-swap capability allows network administrators to plug or unplug them from the SFP slots without having to turn off the power of the connected device.
 Durable Design
The DEM-220T/220R transceivers are packed in a Small Form Pluggable (SFP) metal housing to increase durability.