Ball Bearings
Source: D&D 5.2 SRD Equipment
Cost: 1 GP
As a Utilize action, you can spill Ball Bearings from their pouch. They spread to cover a level, 10-footsquare area within 10 feet of yourself. A creature that enters this area for the first time on a turn must succeed on a DC 10 Dexterity saving throw or have the Prone condition. It takes 10 minutes to recover the Ball Bearings.