Expanding poly slash jackets offer a great way to put papers into three-ring binders without punching them. Made from heavy-duty, waterproof, acid-free, tear-resistant polypropylene. Closed on both sides and bottom to keep contents secure. Expand 3/4" to hold up to 90 letter-size sheets. Diagonally slashed sides make it easy to insert or remove material as needed. Jackets are three-hole punched to fit in standard letter-size binders.