With a smoker box, you can turn your gas barbecue or charcoal barbecue into a smoker. You can choose from pellets with various flavors. For example, hickory, apple, or cherry wood. Place the pellets in the smoker box and place the box on the grill rack. The smoke that releases is absorbed by your dish. That way, meat, fish, and vegetables get even more flavor. Most smoker boxes are made of metal, like stainless steel.