Over the last couple of years Siemens has been redesigning it's line of Interlock Switches and Interlock Switches with Locking. As a result of this activity, and now their availability, interlock switches have been, or are in the process of being obsoleted. The PDF below, "OBSOLETE by Order No." provides the Obsolescence as of this date by Siemens Order No. It also identifies those devices where an announcement has been made of their Obsolescence but no date has been set. The status by Order No. and it's replacement are found in a separate document, "2008 Alphanumeric Price Guide & Cross Reference" for Interlock Switches.