Briggs & Riley Excursion Backpack, Black, One Size Strategic use of lightweight, durable 420D nylon, 600D polyester and water-resistant tarpaulin; contrasting gray heather fabric for modern aesthetic Outer fabrics resist wear, moisture, dirt and abrasion Durable webbing top handle provides a comfortable grip Adjustable sternum straps to reduce neck and shoulder strain Aerated mesh back padding allows air to circulate against body, keeping back cool