Techwin C-band booster Er-doped fiber amplifiers are designed for amplifying single-mode or polarization signal of the single wavelength optical transmission system. The maximum output power is up to 23dBm. Techwin C-band booster Er-doped fiber amplifiers adopt ACC and APP control mode. The output power is continuously tunable and precisely controlled. The power can be set voluntarily as needed by easy operation. Techwin C band booster Er-doped fiber amplifiers have two kinds of package: bench top and module. All systems can communicate with computer through RS232 interface.