Hammer of Thunderbolts

You gain a +1 bonus to attack and damage rolls made with this magic weapon.
Giant's Bane (Requires Attunement): You must be wearing a belt of giant strength (any variety) and gauntlets of ogre power** to attune to this weapon. The attunement ends if you take off either of those items. While you are attuned to this weapon and holding it, your Strength score increases by 4 and can exceed 20, but not 30. When you roll a 20 on an attack roll made with this weapon against a giant, the giant must succeed on a DC 17 Constitution saving throw or die.
The hammer also has 5 charges. While attuned to it, you can expend 1 charge and make a ranged weapon attack with the hammer, hurling it as if it had the thrown property with a normal range of 20 feet and a long range of 60 feet. If the attack hits, the hammer unleashes a thunderclap audible out to 300 feet. The target and every creature within 30 feet of it must succeed on a DC 17 Constitution saving throw or be stunned until the end of your next turn. The hammer regains 1d4 + 1 expended charges daily at dawn.