The combination of the RS Controller, Patented Inverted Vee (NOT NEEDED or AVAILABLE on RVB10 and RVB500) and the Auger Drive is what makes this Revolution™ RVB Spreader work so well. A contractor has the ability to spread any materials demanded by the client with a consistent pattern at the proper speed and with no loss of valuable material. By dialing in the specific flow of material to the auger and then controlling the auger speed independent of the spinner speed the contractor has ultimate control of every necessary component of the hopper spreader.