Backpack of Carrying

This normal-looking backpack is enchanted to make its contents feather-light. The pack itself always weighs 5 pounds, but anything placed inside it does not add to its weight.

This enchantment does not affect the space inside the pack, which is one (1) cubic foot in volume. However, whatever fits into the pack can be carried as though it weighs nothing.

As usual, you can strap items such as a bedroll, a coil or rope, or a waterskin to the outside of the pack.  These items retain their normal weight.