A sex machine is a mechanical device used to simulate human sexual intercourse or other sexual activity. Devices can be penetrative or extractive. The term fucking machine is generally used to describe a penetrative machine which works by the transfer of rotational or reciprocating force from a motor to a directional motion on a shaft tipped by a dildo. A hand-held modified reciprocating saw device is sometimes called a fucksaw, a hand-held modified drill motor rotating device is sometimes called a drilldo, and a modified jigsaw is called a jillsaw. An extractive device works like a milking machine and can be attached to the penis, breast, or other body part.