GPK is a KISSsys based gearbox calculation package which provides the user with 17 basic models of gearboxes as templates. For the current KISSsoft release, the GPK models were improved and the handling was refined. This includes functionalities as the enhanced shaft and bearing calculation, which iterates the shaft diameter based on the available bearing diameters - and the possibility to specify the strength method, individually for each stage. On the other hand, with the new 3-D viewer, it is now possible to accomplish a simulation of the rotation or to visualize the shaft deflection. Finally, with the export and import feature, it is possible to export table data and KISSsoft data from a GPK model and import it into another one. Consequently, the user can apply the new functionalities quickly and efficiently.