For sale is a NEW LOT OF 5 FOILX AIR FILTER 23X16X1/2" Class 1 <76 VL> Specifications Frame: 0.025 aluminium channel Closure: Aluminium blind rivet Filtration Media:Multiple layers of 0.002 slit and expanded aluminium foil Face Grids: Slit and expanded aluminium Tolerances: Length 1/16, width 1/16, thickness 1/32