To determine what model fireplace you own you must find the rating plate. Every fireplace comes with a rating plate that must stay attached to the fireplace. For any of our fireplaces built within the last 10+ years the rating plate will be attached to a wire located near the gas valve. Note that this does often require removing the trim (not the glass window) to access. Most trims can simply be removed by lifting it up off of the hooks and pulled out toward you.