On a direct-vent gas fireplace the brand and model will be posted underneath the fireplaces on a silver sticker. To gain access to this information you will need to lift the bottom louvers of your fireplace. On a wood burning fireplace this information will be places on a silver tag to the left or right of the screen or inside the firebox just above where the brick stops. You will need to know this information in order to replace any parts and address any specific problems with your fireplace.