Similar to the large Deluxe Siler, but with an oversized rectangular plate. This leaves you with the versatility to create the lock design you really want-especially useful in restoring original guns. This has the same deluxe internals at the D-Siler.Jim Chambers has made several improvements to the classic large Siler which include a taller cock to use more of the frizzen face, the half cock notch is changed to allow for the use of a full sized flint and still clear the frizzen, and the toe of the frizzen is changed to allow it to cam over sooner. This combination works faster, gives better spark and extends flint life. Dimension 5 7/8" x 1 3/16". Uses 3/4" flint, #FLINT6F.