Larzuk's Puzzlebox
Larzuk's Puzzlebox is a PD2 item that can add 1-2 sockets with equal chances to an item if that item is capable of gaining sockets.
Its droprate is similar to a high rune and it is mainly used to add sockets to end-game items with a high-rarity corruption.
Caution: Throwing weapons cannot gain sockets, but the puzzlebox will still be consumed if used on one.