Bowl of Commanding Water Elementals

From Dungeon Master's Guide, page 156. Found on Magic Item Table G.

Description
''Wondrous item, rare. 3 lbs.''

While this bowl is filled with water, you can use an action to speak the bowl's command word and summon a water elemental, as if you had cast the Conjure Elemental spell. The bowl can't be used this way again until the next dawn.

The bowl is about 1 foot in diameter and half as deep. It weighs 3 pounds and holds about 3 gallons.