The Ultra-Cell is an aluminum separator style High Efficiency Particulate Air (HEPA) filter, with efficiencies ranging from 95% to 99.99% on .3 micron. Ultra-Cell filters are available in multiple constructions for gasket seal, fluid seal, high capacity, and high temperature applications. Frame material options include fire-retardant and non-fire-retardant particleboard, fire-retardant and non-fire-retardant plywood, 304 stainless steel and 16 gauge galvanized steel. The Ultra-Cell line compliments the Purolator housings. 24" x 24" x 12" nominal dimensions. 24" x 24" x 11-1/2" actual dimensions. Above MERV 16.