13.5" diameterl 14.5" height 60 sq. ft. true HEPA medical filter medium Nearly 15 lbs mixture of solid activated carbon and zeolite Meets HEPA standards, trapping 99.97% of all particulates larger than 0.3 microns Foam sealing gaskets top and bottom Total weight 23 lbs PERMAFILT Prefilter Traps large dust particles Designed to be vacuumed from outside and eliminate costly 3 month filter changes. Pre-filter is included.