This Osprey dry sack holds 35 liters and has a rectangular shape that packs more efficiently in backpacks or luggage compared to round dry bags. The roll-top closure is what makes it waterproof - you roll it down several times and clip it shut, creating a solid seal against water, dust, and moisture. It's made from bluesign approved fabrics that are 100% recycled, and the DWR treatment doesn't use PFAS chemicals, which is better for the environment. The ultralight design means it doesn't add much weight to your pack, making it great for hiking, camping, kayaking, or travel where you need to keep gear dry. You can use it to organize different types of equipment within your main bag or as a standalone waterproof case. Osprey designed this as part of their packing system, so it works well with their other organizational accessories. The material is durable enough to handle rough use while remaining flexible and packable. Whether you're protecting electronics, clothes, sleeping bags, or important documents from rain, splashes, or accidental submersion, this dry sack gives you reliable waterproof protection in a lightweight, eco-conscious package that serious outdoor enthusiasts will appreciate.