"This bookmark is the perfect gift for any book lover, and it's sure to be cherished for years to come." Magnetic Bookmark: It has strong adsorption capacity and will not fall off even if book is 0.4 inches thick. "Our bookmark designs are intended for placement at the top of the book. Size & Material: 3.9x1.2In/10x3cm. It does not hold hard cover of book. max 30 pages at once. Made of PU leather and magnets. leather bookmarks gives less damage to books than metal or plastic bookmarks.