Ideal for shipping, storing, or staining slides. These polypropylene containers hold five standard (3 x 1" or 75 x 25mm) slides. Inside wall features slotted channels to keep slides separated and to make removal easier. Both the end-opening and side-opening versions close securely to keep slides safe. Comes in packs of 25. The side-opening mailer measures 81 x 19 x 31mm.