The present invention discloses a multi-access cannula for use in a variety of surgical procedures, particularly for use in the course of performing conventional open-chest and peripheral access cardiopulmonary bypass. The rotation transmission path forming device can include a drive shaft unit, a drive shaft unit shifting mechanism, and a magazine drive motor module. In operation, heat is transferred by the heat exchange assembly from the system coolant to a facility coolant, and the frame with the associated bulk power assembly and associated heat exchange assembly provides both power and cooling to the electronics rack. The buttstock provides an improvement to the ajustable buttstock used on M4M16 style firearms in cold weather which can become frozen in place in the collapsed position and not provide a proper mounting of the carbine relative to the user.