Wand of Fireballs

From Dungeon Master's Guide, page 210. Found on Magic Item Table G.

Description
''Wand, rare (requires attunement by a spellcaster). 1 lb.''

This wand has 7 charges. While holding it, you can use an action to expend 1 or more of its charges to cast the Fireball spell (save DC 15) from it. For 1 charge, you cast the 3rd-level version of the spell. You can increase the spell slot level by one for each additional charge you expend.

The wand regains 1d6+1 expended charges daily at dawn. If you expend the wand's last charge, roll a d20. On a 1, the wand crumbles into ashes and is destroyed.