The version of RadAjax in the picture you referenced is different than the version you typed. Assuming you want the later, it is from the Q2 2007 SP1 release (Release Notes: http://www.telerik.com/versionnotes.aspx?id=837). This is a very old version, though, so I would encourage you to consider upgrading to the newer, more powerful RadAjax for ASP.NET AJAX (which is obviously based on the ASP.NET AJAX framework). If that's not an option, you would probably be best served by downloading the Q1 2009 version of the RadAjax for ASP.NET Classic to ensure you get all the bug fixes possible.
Hope that helps.