A Dong is an object usually designed for sexual penetration of the vagina, mouth, or anus, and is usually solid and phallic in shape. Mostly include penis-shaped items clearly designed for vaginal penetration, even if they are not true approximations of a penis. People of all genders and sexual orientations often use dongs for masturbation or for other sexual activity. Dongs can be made from a number of materials and shaped like an erect human penis. They are typically 4–6-inch (10–15 cm) in length, about the average length of an erect penis, but some may be longer, and circumference is typically 4–5-inch (10–13 cm).