A dildo is a sex toy, often explicitly phallic in appearance, intended for sexual penetration or other sexual activity during masturbation or with sex partners. Dildos can be made from a number of materials and shaped like an erect human penis. They are typically about the average length of an erect penis, 4–6 inches (10–15 cm), but some may be longer. A dildo's circumference is typically 4–5 inches (10–13 cm).
A dildo is an object usually designed for sexual penetration of the vagina, mouth, or anus, and is usually solid and phallic in shape. Penis prosthetic aids, known as "extensions", are not considered dildos. Some include penis-shaped items clearly designed for vaginal penetration, even if they are not true approximations of a penis. An anal dildo is intended for repeated anal penetration, to be distinguished from a butt plug which is flanged with the intent of remaining in place. People of all genders and sexual orientations use these devices for masturbation or other sexual activity.