The model, developed at the Vienna University of Technology, is a lumped conceptual rainfall-runoff model, following the structure of the HBV model.
The model can also be run in a semi-distributed fashion and with dual representation of soil layer.
The model runs on a daily or shorter time step and consists of a snow routine, a soil moisture routine and a flow routing routine.
See Parajka, J., R. Merz, G. Bloeschl (2007)