Masturbators for men are devices that aid in the act of masturbation. Some masturbators even feature "hands free" operation. These stimulators attempt to recreate the feeling of either oral sex, vaginal sex or anal sex, depending on the device. Most are made of soft jelly, silicone or cyberskin material with a stretchable slit or opening into which the penis is inserted. Some may also feature a built in vibrating bullet for extra stimulation.