Stackable metal cooling racks. Can be stacked or used separately. Bottom rack measures 16” x 10” x 1 1/2” x 3” in height or can flat. 2 middle racks measure 16”x 10” x 3”. Bottoms flex to 3” in height or can lay flat. Top rack measures 13 1/2” x 9 1/2” x almost 4”. Bottom flexes to almost 4” in height or lays flat.