These Magic-Flight Herbal Concentrate Trays enable you to use herbal concentrates and extracts in your Launch Box. Any concentrate that can fully melt to a liquid and leave no residue behind is suitable for use in the screened tray. The unscreened tray works with all types of concentrate that do not completely melt to a liquid; do not use liquid concentrates with the unscreened tray. These reusable Concentrate Trays are constructed from stainless steel to securely and safely vaporize your desired concentrate.