If your enclosure is to be built of combustible materials, then an insulated jacket is required for safe installation of your grill. 

Alfresco AIJ-42 Insulating Jacket for 42-Inch Grill provides a high quality accessory for use with your Alfresco 42-inch ALXE built-in grill. Constructed with durable 304 stainless steel, this insulating jacket is designed to withstand the elements. It is required for use when installing the grill in a combustible cabinet but can also add insulation for non-combustible grill islands.

Features

• Stainless Steel Construction - Made from heavy-duty 304 stainless steel for added durability
• Required for Use - Insulating jacket must be used when installing your grill into a combustible grill islands
• For Use With - Designed for use with Alfresco's built-in ALXE 42-inch grills (ALXE-42)