The new internal geometry of v6 Nozzles is optimised to reduce back-pressure, this ensures smooth,easy flow of filament whilst improving the effectiveness of retractions. The bottom flat surface of the nozzle which flattens down the layer is custom to each nozzle size, for small nozzles a small nozzle tip gives you high precision. On the larger nozzles, a nozzle tip assists in the smooth printing of larger layers.