What are the differences from WGT-702S20, WGT-702, and WGT-702S?

The main different is the fiber optic signal. WGT-702S20 and WGT-702S run in single mode and WGT-702 runs in multi mode. With different wavelength, WGT-702S20 support single mode fiber optic cable in distance of up to 20 kilometers and WGT-702S support single mode fiber optic cable in distance of up to 10 kilometers. The distance that WGT-702 supports is 550 meters using multi mode fiber optic cable.