Rasmussen 20" Natural Alterna Ventless FireStones Single Sided - AFS20-NA enhances your ventless fireplace with a sophisticated, natural look. These firestones are crafted from high-quality ceramic-bonded refractory material, making them heat-resistant and durable. Their neutral tone effortlessly complements transitional spaces and stylishly conceals unsightly burners. Exclusively compatible with Rasmussen Alterna Vent-Free FireStones Burners (sold separately), they deliver long-lasting performance without cracking or popping, providing a timeless accessory for your fireplace.