From Guild Wars 2 Wiki
— Vendor description
- Need to be in melee range to stun.
- Stun is useful to interrupt powerful enemy attacks, such as from Bears and Polar Bears.
- Can be used to pick up baubles and food from a distance, to the end of the whip.
- Can be traded for a Boomerang at the Super Coin Vending Machine after completing Super Adventurer's Quest 2.