This is a pair part for earrings or pias.
Each part has a jump ring on the top, which the hole size is about 0.9mm.
Please note that this pair products are not included with round hoop parts or hook pias parts.
You can get easily those parts in a beads shop, or parts shop for jewelry. Since the hole size is about 0.9mm diameter, you can just put it through hoop wire, which is less than 0.8mm diameter, in case you want a hoop parts.