How to create Multivalue converter in WPF?

We create Multivalue converter when target is associated with multiple source. Let's take an example, I want to display text as a combination of Unit & Value. Then I need to Create a multivalue converter that combines Value & Unit.
Please check below the code for the multivalue converter so you can easily understand it.

 public class NumericalTextConverter : IMultiValueConverter
    {
        public object Convert(
            object[] values, Type targetType, object parameter, CultureInfo culture)
        {
            string rType = "";
            if (values.Count() == 2)
            {
                try
                {
                    var ValueText = (string)values[0]??"";
                    var UnitText = (string)values[1]??"";
                    if (ValueText.Trim() != string.Empty)
                    {
                        rType = ValueText.Trim() + " " + UnitText.Trim();
                    }
                }
                catch { }
            }
            return rType;
        }

        public object[] ConvertBack(
            object value, Type[] targetTypes, object parameter, CultureInfo culture)
        {
            throw new NotSupportedException();
        }
    }