SagsAway Sagging Cushion Support Insert | Sofa Couch or Chair | Extend Furniture Life (Severe Regular (1&rdquo;) x18&rdquo;x20&rdquo;) Follow 3 Easy Steps and Watch Video (before you order) to enjoy restored COMFORT and SUPPORT when inserted INSIDE your zippered cushion cover. 3 steps indicate if this can help your situation. Package = one insert to restore one cushion. Made in USA Cushion Height (-) Sag Depth = Remaining Foam Thickness. Less than 2 of remaining thickness indicates either the cushion foam or the spring deck is too weak. Your measurements determine your results to restore seat cushions, not weak or broken springs No Sags is DIFFERENT. A military grade foam inserted INSIDE the cushion cover to compress the remaining seat foam to increase firmness. Laying it the under the cushion is a mistake and results wont last as the foam product settles into the spring deck STEP (1) Measure for size (Regular) 20" x 18" or (Large) 20" x 27". STEP (2) Measure cushion height with no one sitting. STEP (3) Measure cushion sag depth while sitting. With 6 cushion: less than 3 use 1 Severe (or) sags 3 to 4" use 1.5 Extreme Try One - TEST RESULTS. Then if needed, cut and trim to fit or customize for any size cushion by purchasing an extra insert for additional filler. Instructions and phone help are included. Amazon handles returns within 30 days - less return shipping This military grade foam is easy to cut and modify to fit your cushions. Use a sharp knife and good scissors. Top example, we use a Large 20 x 27 insert and cut off 2. Used the 2 to fill-in for more cushion coverage. Bottom example, we cut a Regular (18 x 20) insert in half, resulting in two 9 x 20 pieces. For two 24 x 36 cushions you would need (2) Large size and (1) Regular size insert. You must have zippered cushion covers. This only works by inserting inside your zippered cushion cover. Any positive results will not last if you simply lay it under your cushion. You must have foam cushions. This cannot work with down cushions. This product works by compressing your remaining foam density for a firmer seat. You must follow the 3 steps to see if you have at least 2&#034; of remaining thickness. If less than 2 your best option is to buy new cushion cores or repair a weak spring deck. Understand that your cushions will continue to sag over time. This is a cost-effective alternative to replacing your cushion cores to extend the life of your cushions and help delay buying new furniture.