Bundles And Beyond adds various types of bundles to the game. They are an awesome utilty item for any kind of resource gathering or adventuring. Theres different types of upgraded bundles with each needing a different material to be upgraded. Some even have power ups like the Silver Bundles "Blessing" power, it gives you resistance for 10 seconds when turned on.
Bundles are upgraded in the smithing table.
EMPTY OUT YOUR BUNDLE BEFORE UPGRADING
Sometimes the game bugs and delets your items when you upgrade your bundle if items are still inside.