Double lock protection: The portable file bag features a left and right double-lock design that provides secure fastening and double-lock protection, safeguarding important papers and preventing items from falling out. Convenient transport for A4 documents: Designed to organize standard-format A4 paper, it easily separates test papers, materials, and business documents. Keeps files tidy and accessible from the outside. Durable document protection: Made from robust PP material, this bag keeps documents dry and secure while effectively protecting them from moisture. It resists fading and deformation, built for long-lasting use. Easy transport: The portable section is reinforced and thickened for simple carrying of documents with strong load-bearing capacity. The bag makes transporting papers easier and reduces effort. Use scenarios: Ideal for office submissions and client files; suitable for classrooms and exam materials; great for travel or fieldwork where moisture protection and organized access are important.