These are nozzles for High Flow applications In doing so, the material melts faster and higher flow rates can be used. A Nickel coating is applied to our Coated Brass nozzles to provide protection against corrosion, erosion, and abrasion. Bondtech Mk8 Bondtech - CHT® Coated Brass Nozzle - MK8 - 1 Pcs (Pick A Size Bondtech Heat Block Nozzle Bondtech CHT™ nozzles split the filament into 3 thinner strands so that the material can be melted from the inside. This way the material melts faster and higher flow rates can be used