Abstract: An optical apparatus can be configured to cover an optical transceiver. At least a portion of the apparatus can be configured to move relative to the transceiver between a block state wherein the apparatus is configured to block transmission from a transmitter of the optical transceiver to a receiver of the optical transceiver as well as block emission from the transmitter to the atmosphere, and one or more transmit states wherein the apparatus is configured to allow at least partial transmission from the transmitter of the optical transceiver to a receiver of the optical transceiver while blocking emission from the transmitter to the atmosphere.

Abstract: A vented module includes a housing portion having a drainage side and a drainage port within the drainage side. The module further includes a flame arrestor including a first surface having a fluid inlet, a second surface having at least one fluid outlet, a labyrinth channel extending from the fluid inlet to the fluid outlet, and at least one mesh screen disposed within the labyrinth channel. The flame arrestor is attached to the housing portion such that the drainage port is aligned with the fluid inlet.

Abstract: A vented module includes a housing portion having a drainage side and a drainage port within the drainage side. The module further includes a flame arrestor including a first surface having a fluid inlet, a second surface having at least one fluid outlet, a labyrinth channel extending from the fluid inlet to the fluid outlet, and at least one mesh screen disposed within the labyrinth channel. The flame arrestor is attached to the housing portion such that the drainage port is aligned with the fluid inlet.