A stupidly durable and functional flight bag/rain cover. This can handle any kind of fly line, as well as bumping a dozen-pound ring into the bladder rock, and still keep everything dry. Throwing in the best and most convenient rain cover I've come across, and even more incredibly handy if you have to pack the bag in the hold of a plane/bus. It can even be packed conveniently in its own pocket. The only minus is that it is not the lightest.
This protective bag can hold an even bigger backpack. I personally use Kajka's 100 liters and it slips into a protective bag like a glove. Qualified protection for air travel when the straps of the backpack do not catch on the conveyor belts. Good buy.
The largest backpack cover found in Finland. Durable and works well on air travel. Time shows resilience relative to those of Osprey.