Packing unit (1) with a packing machine (2) for filling bulk materials (3) in open sacks with a sack suspension device (7), for suspending the open sacks at a filling nozzle (8-10) of a product supply device (11, 13) and filling the same with at least one bulk material. The sack suspension device is provided with at least two selectable product supply devices. The at least two product supply devices and the sack suspension device are movable relative to each other in order to select a product supply device and to suspend a sack by means of the sack suspension device at the filling nozzle of the selected product supply device and to fill bulk material in the open sack by means of the corresponding filling nozzle.