This furnace filter by 3M measures 16 in. x 16 in. x 1 in. and is made of fibreglass. It was designed to capture smoke, smog, and airborne allergens such as pollen, pet dander, and mould spores. It's also perfect against large particles like dust and lint. It meets the American Lung Association Health House Indoor Air Quality Guidelines (1000 Microparticle Performance Rating - MERV 11). This filter can last for 3 months. Filtrete filtering material won't support the growth of bacteria, mould, fungi, or mildew in normal use. No unnecessary antimicrobial chemicals were added.