The OEM Cardinal Expanding Zipper Binder Pocket is designed to keep and protect unpunched documents, photos, and other loose items. Each pocket expands up to 1/2 inch to hold up to 100 sheets of letter-size paper or other accessories. The zipper closure secures documents, while the three-hole punched design allows the pockets to fit easily into any standard binder. Made from durable polypropylene material, these pockets are archival-safe and acid-free, ensuring that they will not lift or transfer inks or toners.