An earring is a piece of jewelry attached to the ear via a piercing in the earlobe or another external part of the ear (except in the case of clip earrings, which clip onto the lobe). Earrings are worn by both sexes, although more common among women, and have been used by different civilizations in different times.
Hoop earrings are circular or semi-circular in design and look very similar to a ring. Hoop earrings generally come in the form of a hoop of metal that can be opened to pass through the ear piercing. They are often constructed of metal tubing, with a thin wire attachment penetrating the ear. The hollow tubing is permanently attached to the wire at the front of the ear, and slips into the tube at the back. The entire device is held together by tension between the wire and the tube. Other hoop designs do not complete the circle, but penetrate through the ear in a post, using the same attachment techniques that apply to stud earrings. One of the ends is permanently attached to a small piece of metallic tubing or a hollow metallic bead. The other end is inserted into the tubing or bead, and is held in place by tension. One special type of hoop earring is the sleeper earring, a circular wire normally made of gold, with a diameter of approximately one centimeter.