Nag Champa Dragon's Blood backflow 24 incense conesBurning time 1 cone: approximately 15 minutes.Incense cones for backflow incense burners. Via the air holes, the smoke flows down like a waterfall and creates a beautiful serene effect.24 conesDoes not work with regular incense burners.How to useBurn the tip of the incense cone and wait for it to burn evenly. Blow out the flame and place the cone on the backflow incense burner.