In particular, optical transceivers must match their wavelengths on both ends. In a fiber-optic link, where data is transmitted from one end to the other, the fiber optic transceiver is responsible. When it comes to the connection between two fiber optic transceivers, the following four factors should be taken into considerations: wavelength, speed, fiber type, and the connection to switches. Matching the correct wavelength with the right fiber type and application is essential to ensure: The most commonly used SFP optical modules operate at 850nm, 1310nm, 1490nm, and 1550nm. The topic of specifications and physical traits is one aspect of this question; another often-overlooked detail is the color of the pull tab.