This is a 0.5mm E3D replacement nozzle for the E3D V5 and V6 hotend assemblies for 1.75mm filament.

The brass nozzle is a great general purpose, low cost option making it a favourite choice in the 3D Printing community. Brass has a great balance of properties it is thermally conductive, machines precisely and easily even with very small nozzles and doesn't corrode or pit so retains a smooth surface finish for cleanly laying down extruded filament. The top of the nozzle is threaded in order to fit into the E3D V5 Heater Block or the E3D V6 Heater Block.

It is good to keep in mind that brass nozzles are vulnerable to abrasive erosion by more Exotic Filaments like carbon-fibre filled materials, metal powder filled materials and glow in the dark filaments and also may be damaged by nasty head crashes.