The Seifert 400020100 Spare Filter Media can be used with the 204 x 204 mm filters and fan filter assemblies. Standard color is white. Sold in a set of 6. Comparable to Fandis M13FPFK. The Seifert 400020100 filter media is washable up to 10 times. It is made from thermo-linked progressive structure synthetic fiber and can be cleaned by rinsing, spraying or beating. The working conditions of the environment as well as operating period & the amount of dust accumulated affect the rate of replacement. Filter media that is unclean reduces filter efficiency which can result in insufficient or total lack of ventilation.