Universal Grease Range Hood Filter - trim-to-fit. Replaces any filter up to 15" X 18" with a frame thickness as small as 11/32" FEATURES: Replaces over 1,000 sizes Trims to exact size Easy to assemble Easy to follow instructions printed on filter box. Kit includes 4 frame rails, 1 trimmable expanded metal mesh pad, 4 corner connector clips Tools required: 1) Scissors 2) Tape Measure 3) Sharp Knife Filters grease. Can be used in ducted range hoods, microwave ovens and other applications requiring grease elimination. Replace every 9-12 months. Constructed of dense layer of expanded metal.