These Reversible Waterproof Rain Covers are tailor made to fit Eberlestock's smaller backpacks, in the size class of the Gunslinger and the X1. The G2RC is big enough to go over their daypacks when they're loaded up, and can even cover a gun in the scabbard. Or, you can leave the gun uncovered in case you're in a place where you think you'll need it quickly. The blaze side is a great way to flag your pack if you remove it to make a stalk.
Why offer a rain cover when their pack fabric is waterproof? Think driving rain, when its impossible to keep the innards of a backpack dry without an honest rain cover. If you're going to be out for an extended trip in wet weather, or you'll be bivvying your pack, you'll appreciate having a nice rain cover along.