Ball Bearings (Bag Of 1,000)

Source
SRD
Cost
1 gp
Weight
2 lbs.
Description
As an action, you can spill these tiny metal balls from their pouch to cover a level, square area that is 10 feet on a side. A creature moving across the covered area must succeed on a DC 10 Dexterity saving throw or fall prone. A creature moving through the area at half speed doesn't need to make the save.