The main difference between SFP modules operating at 1310nm and 850nm is the wavelength at which they transmit optical signals. Each wavelength window has distinct physical properties, advantages, limitations, and ideal use cases that make it suitable for particular applications. These compact optical transceivers offer a access and ring network, storage network, and. For fiber optics with glass fibers, we use light in the infrared region which has wavelengths longer than visible light, typically around 850, 1300 and 1550 nm.