A chassis and associated telecommunication circuit card are disclosed. The chassis has heat dissipation structures and may accommodate a high density of the circuitry cards. Embodiments may include one surface with one or more ridges for rigidity and ventilation and fin slots for receiving circuit card guide fins. Embodiments may include a surface with knockouts for receiving circuit card guides. Embodiments may also include multiple bracket hole patterns for mounting brackets for different racks or for a single multi-rack bracket having more than one mounting hole pattern. The circuit card includes conductor structures such as multiple board layers with paired and segregated conductors. The circuit card also includes some components positioned to cooperate with the ventilation structures of the chassis and includes some components chosen for low-power consumption or reduced flammability.