(Soul Sticks) Rosemary Backflow Incense Cones 10 Cones/Pack, 12 Packs/Box BACKFLOW CONES: Backflow cones are specially designed with traditional herbs & resins that create a thicker smoke that cascades down rather than rising up like a traditional incense cone. We do not use any artificial chemicals to make the smoke thicker and all our cones are dipped in concentrated fragrance oil for at least 48 hours, resulting in a pleasant smell. HOW TO BURN & USE: Light the incense cone using a lighter or match. The bottom of the incense cone should be aligned with the hole of the backflow incense burner. It is most effectively used in a non-windy environment to prevent the smoke from dissipating. Each cone will burn for about 15-30 minutes