Lightning Rod (5e Equipment)
From D&D Wiki
A lightning rod features a spiraling pair of a green-blue stem and a yellow-green stem. In place of an attack you would otherwise be able to make, you can do one of the following:
Melee Weapon Attack. You swing the rod, which on a hit deals nonmagical slashing damage equal to 1d4 + your Strength modifier, plus 1 magical lightning damage.
Ranged Spell Attack (costs 1 mp). You swing the rod, and a mote of lightning leaps from the tip up to a range of 30 feet, which on a hit deals 2d6 lightning damage. You add your Intelligence modifier to the attack and damage rolls of this attack. You have advantage on the attack roll if the target is wearing armor made of metal, or is soaked in water.