A vibrator, sometimes described as a massager, is a sex toy that is used on the body to produce pleasurable sexual stimulation. There are many different shapes and models of vibrators. Most modern vibrators contain an electric-powered device which pulsates or throbs. Vibrators can be used for both solo play and partnered play by one or more people. Devices exist to be used by couples to stimulate the genitals of both partners. They can be applied to erogenous zones, such as the vulva, vagina, penis, scrotum, anus, or rectum for sexual stimulation, for the release of sexual frustration and to achieve orgasm. Vibrators may be recommended by sex therapists for women who have difficulty reaching orgasm through masturbation or intercourse.