This Brouilleur is for the tech-freak Absintheurs (like us). You first pour some Absinthe in the Absinthe glass. Then you place the Two level Absinthe Brouille on top.
Another nice Absinthe Brouilleur that works the opposite way. Which means you fill the glass with water, then you place the Brouilleur on top and fill the cup with Absinthe.