We use the fitted trim approach to seal up the doors and lids. This smoker comes with our 2 inch insulated firebox. Also features a winch operated adjustable cabinet gate so you can choose to use your cabinet how you need as a cooker, warmer, or shut off to conserve wood. This smoker features both traditional flow and reverse flow systems to give you a broad range of versatility. On order you can customize your cargo space to add propane burners, log bins, lockable storage bins, tool boxes, and much more.