Need more current or higher voltage to run your large-scale layout? This may be just what you need; output currents up to 5 amps and output up to 20 volts will make those G-scale locos sing. A tethered walkaround cab is included (should you choose to implement it; this adds a great deal more flexibility and user-friendliness to the beast, but please note that one should not unplug the cab when power is on, as it will result in the train taking off at full speed and the directional relay disengaging (neither of which is a good thing). If your layout is relatively small, and you can walk easily from end to end using a long coiled phone cord, then this will probably be just what you need.
If, however, your layout is of such a size or configuration that you really need several places to plug in the throttle, then you should consider the “semi-tethered” implementation as shown on another throttle design, but readily adaptable to this one.