The Rotagrid is an optional accessory for the Rotalux softbox. The Rotagrid is a combination of external diffuser and a grid, which can replace the standard external diffuser. The Rotagrid reduces the spread of light and offers sharper shadows.The RotaGrid offers a directional light with greater contrast. Grids in general are reducing the spread of light. The RotaGrid includes the Diffuser and the Grid made as one part.