36" builders woodburning firebox. Firebox includes stamped louvers, cast-iron grate, wire mesh screen, and refactory concrete liner with floor. Approved for use as a wood burning fireplace or for use with vented gas log sets or vent-free gas logs. Accessory hood and FMI venting pipe must be installed when using vent-free logs. Approximate product dimensions: 38" W. x 37-1/2" H. x 21-1/8" D. IHP venting pipe must be installed, which have been designed to fit and tested for this fireplace system.