public class ProductGrid : GridIn this example, the Price column is being formatted using the ToString method with a "C2" format string, which formats the value as currency with two decimal places. The package/library that provides the IGridColumn interface is likely to be a UI framework or library for building data grids, such as Telerik UI for ASP.NET MVC or Infragistics IgniteUI.{ public ProductGrid() { Column(x => x.Name); Column(x => x.Price).ValueFor(x => x.ToString("C2")); } }