Size...30-45L Tactical Assault Backpack Capacity: 34L Approximate Size: 11" x 18" x 12" / 28 x 45.5 x 30cm (Width x Height x Depth). This not-so-large military backpack is made of high-density fabric, making it durable and waterproof. Features double stitching, heavy-duty zippers and utility-style cord pulls, side and front load compression systems, comfortable padding on the back, and breathable mesh padding on the shoulder straps. The military backpack also has a hydration function and is compatible with a 2.5L hydration pack (hydration pack not included), and can be used as a hydration backpack or an outdoor camping hiking backpack. This tactical assault pack backpack can be used as a 3-day assault pack, hunting backpack, survival backpack, trekking backpack, or everyday backpack. This tactical backpack has a MOLLE (Modular Lightweight Load-carrying Equipment) system. Unlike many tactical backpacks, it has a seamless construction. The spacing between MOLLE is less than 1/2 inch.