Bowl of Commanding Water Elementals

This heavy glass bowl weighs 3 pounds and can hold 3 gallons of water. While it is filled, you can use an action to summon a _water elemental_ as if you had cast the _conjure elemental_ spell. Once used, you must wait until the next dawn to use it again.

Source: Level Up Advanced 5e · OGL-1.0a · 5.1