This yarn is a specialty yarn by Bergere de France. Here is the description they provide:

Aromalaine is a pure wool yarn embedded with microcapsules containing essential oil of Niaouli. Attached to the surface of the fibers, some microcapsules are crushed whenever you knit or wear the yarn: their precious active ingredients are released into the surrounding air. The microcapsules remain active through at least 20 wash cycles.

Use any patterns designed for Magic yarn

Aromalaine is a pure Woolmark wool, safely machine-washable in lukewarm water 30°C.