Abstract: An optical transceiver module includes an electro-optical transmission assembly and an electro-optical receiving assembly both mounted on a common printed circuit board and enclosed by a top shell and a bottom shell of an electromagnetically shielding transceiver module. The housing has optical connection openings and an electrical connection opening. The serial optical signals of a first Bit-rate of several Gbit/s and more are converted to serial electrical signals and are multiplexed to parallel electrical signals at a lower second Bit-rate. Reducing the Bit-rate and thus reducing the electromagnetic frequency reduces the risk of electromagnetic interference on the printed circuit main-board. The optical connection openings have a first and a second gasket for reducing the electromagnetic radiation emerging out of the housing through the optical connection openings.