Reusable, water-resistant transit sack is perfect for expediting paperwork by mail or messenger. Ideal for intra-company communications as well as company to company deliveries. Contents are kept confidential by looping self-locking security seal (sold separately) through grommet and zipper pull. Durable vinyl with reinforced seams. Framed ID window. Expandable sides make it ideal for bulk mail. Closure: Zipper; Material(s): Vinyl; Width: 18 in; Depth: 4 in.