ncense Burner Backflow Incense HolderDescription Incense Burner Backflow Incense Holder, Ceramic Handcrafted Backflow Incense Burner with 10PCS Incense Cones for Home Decor Yoga Black The Backflow Principle: because the density of smoke is heavier than the air density, smoke stream from the high down like a waterfall How to Use: Choose a flat, windless place Lit up the top of the backflow cone, burn it fully in case you have to lit it again Place it on the incense burner, and wait a few