This can be used either as a low-cost non-speed proportionate control similar to the Vari-Speed Control, or with a suitable speed input, will give economic speed proportionate output. Currently, it is available for Turbo Jet.  In either format it shares the same simple calibration procedure as the Vari-Speed, and with a ground speed input from either a supplied GPS receiver, or using a mechanical or radar speed signal from the tractor ISOplug, it will match the speed of the feed motor to the forward speed, to maintain the selected application rate. Economic and easy to use, with simple audio / visual alarms to alert the operator of any malfunction or low hopper contents.