Stadler Form Oskar Filter Packs To remove all bacteria from the air it is wise to replace these filter cassettes every two months in your Stadler Form Oskar. This way you keep a fresh and bacteria-free air indoors. The water remains as clean as possible in this way, which in the end means the changing of the air. The Stadler Form Oskar Filter Packs ensure an ideal and clean emission from evaporators. About Stadler Form In 1998, Martin Stadler started his business in household appliances from a garage (with the Fred humidifier as the first product). In just fifteen years, Stadler Form has grown into a brand of international allure with products that are more than just a household appliance. Stadler Form is distinguished by the unique Swiss design. Stylish and sleek, innovative and unconventional: the products from Stadler Form are - besides of excellent quality - a beautiful addition to any interior.