Material: PP micro-fiber Feature: low resistance, high dust-hold capability, high filtration efficiency, resistance to acid and alkali Meeting American Ashaer standard Filtration efficiency: 45%, 65%, 85%, 95% Especially suitable for environment of high humidity Width: 1.5m and in roll package Can be used for making into bag type and plated air filters, which are widely used for air cleaning in large shops, airports, schools and hospitals