Permanent floating filter, by the Finum brand.
Made of black plastic, it works for both teapots and cups.
You can place any type of spices in the floating filter and add it to the drink you want (tea, coffee, wine, etc.). You can use any spice such as nutmeg, cinnamon, etc.
Its raised lid makes it easy to remove from any hot beverage as the filter and lid do not separate in this process. Once the infusion is finished, the lid can be used as a plate to put the filter in and avoid dripping.