Potion of Invisibility

From Dungeon Master's Guide, page 188. Found on Magic Item Table D.

Description
''Potion, very rare. 0.5 lbs.''

This potion's container looks empty but feels as though it holds liquid. When you drink it, you become invisible for 1 hour. Anything you wear or carry is invisible with you. The effect ends early if you attack or cast a spell.