Ice Ball Maker
According to this article by The Spruce Eats, the ice ball melts slower than normal square shaped ice, therefore preventing watered-down drinks.
Which is why you are going to need this ice ball maker. So that you can make ice balls at the comfort of your home and enjoy cold drinks in your own sweet time.
It allows you to make four ice balls at a time. Each ice ball has a 4.5cm diameter.