It's lightweight and adjusts to fit my backpack snugly. The black cover is perfect for those of us who like to hide our packs for day hikes. Put on your back cover, find a little brush  20 or 30 yards off the trail and it's gone! Just observe very carefully where you put it!

There are 2 things missing and although no other products do this, why not? 1. If you hang your backpack from a tree (critter protection) the gap in the back will let water in (this is bad). 2. If you have your back cover on and want to attach wet gear on the outside where it belongs, you can't do that either. The times when you need to do this coincide almost exactly with the times you need a pack cover.