UltraNumericEditor Version 18.2. Looking for a working example where the user can enter the whole percent value they want (e.g. 0.55), have 0.55% displayed in the control, but have the underlying value be 0.0055. It is rare I need post questions but I have been unable to solve this after a day of searching. I think I am close after re-purposing the IEditorDataFilter code from here ( http://devcenter.infragistics.com/Support/KnowledgeBaseArticle.aspx?ArticleID=4877 ). This DataFilter properly sets the control's Value to 0.0055 but the control loses the displayed value. It goes blank! What am I missing? Even though I have been developing with Infragistics controls for over 10 years, I cannot articulate what a DataFilter is or how to properly use it. Perhaps there is no "built-in" way of doing this and I need to instead use the after exit edit mode event to divide by 100 and manually set the Value to 0.0055 and allow the format string to display 0.55%? Thank you!