It is made of high-quality environmentally friendly materials (vintage kraft paper), retro and nostalgic, high-quality cloth is easy to wrap, good stiffness, flat and will not wrinkle Modern design with multiple functions, 25 sticky notes, CD card slot, business card pocket Ultra-thin, portable and practical. Small size, light weight and easy to carry. The cover calculator is powered by solar energy, which solves the problem that you are worried about not being able to use without electricity