Where can I find Filter sleeves in Fernwald?

Filter sleeves can also be found in these cities:

Buseck Butzbach Giessen Hüttenberg Langgöns Lich Linden Lollar Mücke Pohlheim Rabenau Rockenberg Staufenberg Wettenberg Wetzlar

You can also find this in Fernwald:

Fish Croissants Flour Wheat Breads Diet Products Ready Meals Energy Drinks Espresso Beans Food Flips