This specialized Rear End Cap turns any BrightLine Bag into a backpack (with limitations).
This End Cap has backpack straps built in, but doesn’t look like a backpack when the straps are not in use. It's easy to deploy the straps in less than 20 seconds. And then it's easy to stow them when you don't need them.
Now you have the ability to throw your (small) BrightLine Bag onto your back and use both shoulders to carry the load and be hands free when necessary.