Mybecca Set of 4-18 x 18 Super Premium Hypoallergenic Stuffer Pillow Insert Sham Square Form Polyester, Standard/White - Made in The USA Down-like comfort - Odorless Resilient / Refluffable Measurements are seam to seam - After filling, pillow will decrease about 10% - 15% in size. Order one size up! 100% Hypoallergenic Polyester - MADE IN USA- Crafted By Mybecca inc Note To Customers: For best results this insert is recommended for 17" x 17" or 16" x 16" sham covers, If your cover is 18" x 18" we recommend 20" x 20" inserts to provide a plump and full pillow from corner to corner. Filled with 100% Virgin polyester non allergenic , soft and sumptuous yet firm.