Rasmussen 24" Dark Gray Alterna Ventless FireStones Double Sided - DF-AFS24-DG offers a bold, sophisticated look for your ventless fireplace, enhancing both sides with its rich dark gray tone. Crafted from durable ceramic-bonded refractory material, these firestones are heat-resistant and built to last without cracking. Ideal for concealing burners, this dark gray set complements modern and transitional decor beautifully. Compatible exclusively with Rasmussen Alterna Vent-Free FireStones Burners (sold separately).