Connection for temperature-controllable exchangeable block

The present invention relates to an apparatus for mixing and controlling the temperature of laboratory vessel contents with an accommodating device in detachable connection with an exchangeable block for accommodating and controlling the temperature of laboratory vessels and with a drive by which the accommodating device can be set in a mixing motion, and with a temperature control device with a heat source or sink in heat-conducting connection with the exchangeable block at least through in each case at least one adjoining contact face firstly on the accommodating device and secondly on the exchangeable block, which is characterized in that the detachable connection is maintained by a spring element which, by virtue of its spring force, horizontally clamps together a first undercut between the accommodating device and the exchangeable block in at least one first direction.