This is a dry bag designed to be stored in the main compartment of the ILBE (Improved Load Bearing Equipment) backpack, which was adopted by the US Marine Corps in the 2000s and used WOODLAND MARPAT. This bag, developed in collaboration with SEAL LINE, a brand renowned for producing durable dry bags, exhibits exceptional waterproof performance. Made of 210D (denier) Oxford nylon and coated with high-strength polyurethane for added durability, this bag keeps your belongings dry. It features SEAL LINE's unique DrySeal roll-down closure, which is secured with buckles. It also includes a manually operated air purge valve that can be opened during sealing to release excess air, reducing the bag's bulk when closed. I purchased this at a Seattle recycling shop 9 years ago. I brought it home but have kept it in storage without using it. The ones barely available in Japan are the #02179, 65L models. This is the #02177, 56L model, so it may offer a wider range of uses. I have not found any tears or damage upon inspection. As the photos show, it stands upright when filled with air. I believe there are no air leaks from the valve. However, please understand that this item has been in someone's possession before and purchase it with the understanding that it is a deadstock item.