This item has fallen out of favor for daily use, but merchants would still pay 130% of the purchase price for it. To sell it, place the pack on the ground and interact with it. A stealthy Daru will snatch the pack and leave the gold in your Bag.
Use:
Place the trade pack on the ground. Dropped trade packs can be picked up by anyone.
Effect:
Carrying heavy objects reduces movement speed and prevents teleporting or gliding.