A single key trap for use with Schlage modular cylinders including Primus and Everset high security mortise cylinders. Specify 1 1/8" or 1 1/4" cylinder.  Includes special link that replaces the mortise cylinder cam. The single key trap measures 3" x 4" x 2-5/16" high.  Cylinders not included.  Not for use with interchangeable core cylinders.