When 3D printer filaments like PLA, ABS, PETG, and nylon are reinforced with carbon fiber, the result is an extremely stiff and rigid material with relatively little weight.
The trade-off is the increased wear and tear on your printer’s nozzle, especially if it’s made of a soft metal like brass. Even as little as 500 grams of this exotic 3D printer filament will noticeably increase the diameter of a brass nozzle, so unless you enjoy frequently replacing your nozzle, consider using one made of (or coated with) a harder material.