This is a set of clothes or accessories for figures.
From Good Smile Company:
This hand parts set for use with your Nendoroid Dolls is being rereleased! These hands can be used with your Nendoroids as well! 6 different pairs of standard hands are included featuring various expressive hand parts and hand parts for holding objects. 3 additional pairs with joints at the wrists are also included, making for a total of 9 pairs of hand parts.