Applicable Format--Our clear book covers is designed to fit A4 Notebooks and books (297mm x 210mm). Adjustable Design--It adopts an integrated design, which can cover thick books, and the width of one side of the book cover can be adjusted at will, which is convenient to adapt to the thickness of different books. Waterproof Material--Made of PP, which is waterproof, can effectively protect the book from getting wet. Strong flexibility, no deformation after curling. Thicken Clear Book Covers--Thickened PP, durable and reusable, wear-resistant, longer use time. Perfect Protector--An effective little helper to help you protect exercise books, folders, school cases & books from dust, dirt, humidity, bending, tearing and dog-ears.