This is where the long-range 10G optical module becomes the unsung hero of modern networking. These powerful transceivers are the workhorses that convert electrical signals into light, beaming 10 Gigabits per second of data over fiber optic cables for distances of up to 10 kilometers and beyond. 850nm (with multi-mode MMF), low cost but short transmission distance, 100M rate can transmit 2km farthest; 1G rate can transmit 550m farthest; 10G rate can transmit 300m farthest; 40G rate can transmit 400m farthest; 25G. The transmission distance of optical modules is divided into short distance, medium distance, and long distance. Short distance transmission usually refers to transmission distances below 2km, with a medium distance of 10-20km.