Brass material advantage: The heat conductivity of brass is 7 times as high as that of stainless steel. MK10 hotend structure only allows filament to have little contact with the nozzle. The material of the nozzle must be brass to ensure filament’s temperature is the same as the thermistor, so it make the melt plastic more smooth. But the heat conductivity of stainless steel is so poor, it is unscientific and irrational used on MK10 nozzle. Quantity and specification: M7 thread nozzle, diameter size 0.2mm 0.4mm 0.6mm 0.8mm 1.0mm, 2 pieces of each size. Compatibility: Fit with MK10 hotend M7 thread aluminum heater block, such as FlashForge Creator Pro, FlashForge Creator X, FlashForge Dreamer, Idea, Builder PowerSpec 3D, Pro PowerSpec 3D X, Wanhao Duplicator 4S, Wanhao Duplicator 4X, Wanhao i3, etc. Multi Size: There are 5 commonly used sizes of nozzle diameter. You can experience different filament feeder rates.