The ComfortMove, the CorrectSit and the ErgoSolex models are interchangeable amongst different users, as long as there is no significant difference in body height or work surface height. The function of the ErgoDynamic is based upon the height and the weight of the user, and therefore not interchangeable amongst different users without adjusting the settings first. Directions for adjustment: turn the weight knob at the front, under the seat. After loosening this knob you can shift it up (for a lighter setting) or down (for a heavier setting). See also the instruction video.