Tough and big, these side-loading envelopes boast sturdy gussets. Archival-quality envelopes are perfect for long term storage of important documents. Heavy-duty polypropylene resists tears and repels moisture. Hook-and-loop closure. Acid-free. File Jackets/ Sleeves/Wallets Type: Expanding Envelope Jacket; Material(s): Polypropylene; Height: 11 5/8"; Width: 9 3/4".