Contemporary Crushed Glass Media for either Vented or Vent-Free applications, come in a variety of colors! Glass can be used on G21, or Loft Vent-Free systems, or a number of Vented burners as well. It can be used to dress up the floor of the fireplace, and conceal gas lines, while concealing the edges of the burner if desired. If you have questions about which burner system/log type is right for you, give us a call at 615-255-4551.