Protect your favorite books with these colorful book sleeves. Made in 3 different sizes to perfectly fit whatever book(s) you have. I try my best to keep my books looking nice when I travel with them. I made these to protect the edges of my favorite books, and they work great! I can slide the book and cover into whatever bag I have, and it fits perfectly. Sizes: (Lying Flat, Not Folded) Small: 8 inches x 13 inches Medium: 10 inches x 15 inches Large: 13 inches x 18 inches Which Size fits Which Book? Small: pocket-sized, paperback books. My Kindle (5in x 7in x 0.5in) also fits, but it's an older generation (so don't trust me that it will fit your Kindle too!) Approximately a 7in x 5in x 1in book. Medium: The average book. Regular paperback and smaller hardcovers. Approximately an 8.5in x 6in x 1.25in book. Large: Hefty Hardcover Harry Potter Books! Think Volumes 4 - 7. Approximately a 9.5in x 6.5in x 2.5in book.