handles difficult materials Oscillating plate hopper provides hang up-free flow for the most difficult-to-handle materials, such as fly ash, powdered resins, and water-soluble salts, without vibration, prodding, or steep hopper angles. Also, the oscillating plate assembly can be custom retrofitted to any existing hopper shape, including conical, chisel, wedge, pyramidal, and Diamondback. Diamondback Technology, Atascadero, CA