This is a special nozzle that is only needed for specialty filaments containing an abrasive filler.
For example, carbon-filled, glass-filled, or metal-filled Nylon or ABS.
Since it is more expensive than a regular nozzle, you may want to reserve its use to only times when you are actually using the specialty materials, since a clog could occur and the nozzle may not be cleanable.
Also, be sure to store (all) your filaments in closed containers, zip-lock bags, or other ways that keep them clean of dust.
