The standard nozzles come with a 1.5mm hole, these nozzles can be drilled larger by the user if required. For smaller nozzles sizes, under 1.5mm hole size, the MD E3D adapter nozzle has a threaded hole for screwing in E3Ds Volcano nozzles with sizes of 0.4mm, 0.6mm, 0.8mm, 1mm, and 1.2mm. The E3D Volcano nozzles that we ship are the standard brass version. If you would like other materials types please use E3D's website. Purchase the MD E3D nozzle adapter and the corresponding size you would like.