The VCS-20A talk set from EXFO E.O. Engineering Inc. is suitable for long-haul applications where total fiber attenuation can be the highest. The units, which allow users to communicate over optical fiber, have a dynamic range up to 50 dB and are available at the 1310- and 1550-nm wavelengths. The VCS-20A utilizes time-division multiplex transmission and is compatible with the company's FOT-920 MaxTester and FTB-300 Universal Test System. Single- and multimode versions are available.