This paper describes several versions of a single, simple device to provide rotary and linear motion within a vacuum chamber without causing even a temporary rise in pressure. Through the use of metal gaskets, bellows, seals, and magnetic couplings, many difficulties arising from the transmission of rotary and linear motion through vacuum‐chamber walls are overcome. In the device described, freedom of rotation is unlimited in either direction, but linear movement is limited to 2 in. Actually, stroke limits are determined by choice of bellows and space considerations. The device makes use of magnetic coupling for the rotary component, and a bellows‐sealed, lead‐screw mechanism controls linear movement.