Our vented oclearance box allows you to install a gas or propane fireplace where you do not presently have one. This unit can be set oon the floor up against a wall, with the chimney being run up and through the ceiling and roof. The gas line passes through the floor or back wall. The fireboxis then framed and drywalled, creating a shallow [approximately 13"] chimney breast, also known as a chase. A cast iron or tiled front can then be installed over the facing material of the framed structure. A mantel wraps around the front and finishes off the installation.