In a content processing device, a set of media channels to be provided in a graphical user interface is identified. As actions are performed, the user can be presented with different forms more applicable to a current task being performed. A pair of mower unit support arms are respectively mounted to forward outer locations of the carrier frame for pivoting vertically between horizontal first positions, wherein they dispose the mower units in respective operating positions, and vertical second positions, wherein they dispose the mower units in raised transport positions. The input resistance and the capacitance set a time constant for the circuit.