Super light weight, but also seems very durable and well-made with stretchy elastic. Will definitely protect a small to medium-sized pack and survive many hikes in the rain. But with a little imagination, it could have many other uses. One side is dark to hide your gear, but turn it inside out and the other side is reflective, to reflect the heat of the sun away from your gear. Perhaps it could also be repurposed as a mini sun oven reflecting heat to a central point to warm food/water. Or it could be used to collect/carry water, or even food/plant material. It could also be used as a cover for items other than a backpack - like your boots or your tech, or even over your head if you don't have a hat. It could line a makeshift basket to make it waterproof. If you close it up at the elastic, you could even make a sack out of it and hang it over a high branch to keep food safe from insects/animals. A simple product that can be handy in a variety of ways, if you think outside the box.