These Prostand textbook covers are designed specifically for 9th grade Russian language curriculum books to keep them clean and intact throughout the school year. Made from transparent polyethylene, they shield pages and bindings from moisture, dirt, and general wear without hiding the original cover art. The set includes 10 pieces in two different sizes to accommodate various book dimensions, providing five covers measuring 262 x 425 mm and five measuring 245 x 357 mm. This variety ensures that students have the right fit for their specific textbooks, helping the materials stay in good condition for the duration of their studies.