UploadedFiles.Item(0) to C#

[Moon]

In my VB code I have:

 

        Public Function GetExtension(ByVal radFileUpload As RadUpload) As String

            Dim fileExtension As String = String.Empty
            If radFileUpload.UploadedFiles.Count > 0 Then
                Dim validFile As UploadedFile = radFileUpload.UploadedFiles.Item(0)
                fileExtension = validFile.GetExtension
            End If
            Return fileExtension

        End Function

But when i convert this to C#, I get an error on the Item(0):

 UploadedFile validFile = radFileUpload.UploadedFiles.Item[0];

It says Telerik doesn't contain a definition for Item.

How do I write this in C#?

thanks.

I have:
using Telerik.Web.UI;

thanks.