Rasmussen 24" Light Gray Alterna Ventless FireStones Single Sided - AFS24-LG adds a modern, neutral accent to your ventless fireplace with its soft light gray tone. Constructed from durable ceramic-bonded refractory material, these firestones withstand high temperatures, offering lasting beauty without cracking. Perfect for concealing burners, this set complements contemporary and transitional decor. Compatible exclusively with Rasmussen Alterna Vent-Free FireStones Burners (sold separately).