Telecommunications chassis and associated modules for use with the telecommunications chassis are disclosed. Embodiments of the telecommunications chassis include structures such as horizontal channels and/or horizontal surfaces with ridges and/or slots in one surface and slots in ridges of another for receiving edges of modules that mount within the chassis. Other structures of embodiments include divider slots in the horizontal surfaces that receive edges of divider walls to fix the divider walls in place, heat baffle surfaces included within the chassis, and/or cable guides with radius limiters. Module embodiments include structures such as faceplates with angled portions with fiber optic cable connections directed toward the fiber cable's direction of travel. Other module structures include shells that enclose the circuit board and/or provide angled portions with fiber optic cable connections. Module embodiments may also include circuitry for converting electrical signals to optical and optical signals to electrical, and the circuitry may selectively operate at multiple data rates.