White block accepts pen, pencil, or marker. Simply write contents, instructions or patient ID's. Easy-to-close single track zipper with easy to open lip make this multi-purpose polybag durable as well as reusable for unit does and prescribed medications. Clear so contents easily identified. No side seal allows for maxiumum width use. Offset lip permits easy separation. Ridges on inside lip make gripping easier. Add a label or hot stamp for branding or identification.