They are sisters, not twins
This is a pair of earrings.
It contains two jump rings to allow the faux leather earrings to lay flat. The earrings are hypoallergenic. 
Both fish earring hooks and jump rings are made of silver plated alloy, which is safe for your skin to prevent irritation or reactions.
The earring backs are made of clear silicone resin allowing for comfort and the earrings will not slip or move around.