Schlage Primus cylinders provide a special dual-locking feature that delivers
                                      excellent protection against physical attack and virtually eliminates unauthorized key
                                         duplication. These high-security cylinders can be easily tailored to fit your exact
                                        situation. Equally important, this revolutionary new system remains compatible with
                                                         numerous other Schlage key sections.
                                        The heart of the Primus system is the patented “side-bit milling” along the key. This
                                        unique geometric contour interacts with a matching set of finger pins. When a key
                                          with the correct side-bit milling combination and a proper cut is inserted in the
                                        cylinder, a conventional shear line is formed and simultaneously the sidebar gates of
                                       the finger pins move into position to permit the cylinder to unlock. This dual-locking
                                                principle makes the Primus cylinder highly resistant to picking.
                                        For optimum security and to assist in reducing costs, the Primus key is designed to
                                        enter a selected standard Schlage keyway, but the standard key cannot enter the
                                                              unique Primus cylinder.
                                        Schlage Primus cylinders also include a product line that delivers extra protection
                                                        from drilling and other physical attack.

                                       The Primus system eliminates unauthorized key duplication and provides five security
                                          levels with increasingly restrictive key availability coupled with more selective
                                                  signature verifications and side-bit milling combinations.
                                         Dual-locking allows all Primus cylinders to achieve the same high degree of pick
                                         resistance. But if your installation requires the utmost protection against forceful
                                                 attack, choose the Primus 20-500 High Security cylinder.
                                        With hardened, drill-resistant pins strategically positioned around the cylinder, the
                                       20-500 meets Underwriters Laboratories Canada's tests for drill and pick resistance
                                                              (ULC file #CBP 532).

The Schlage Primus high security cylinder is precision built to extremely close tolerances and the highest standards of quality. These "dual-locking" cylinders consist of two independent locking mechanisms, operates by a single specially designed Primus key. In addition to a standard 6 pin tumbler mechanism there is a locking sidebar which is independently controlled by a set of 5 fingerpins that interface with the side-bit milling (SBM) on the patented Primus key. Schlage Primus products are covered by issued and pending patents in the U.S.A. (4756177 and 4815307) and foreign countries (New Zealand: 219080).
The side-bit milling operates the second locking mechanism and can be thought of as a unique "fingerprint" of the key.

Primus cylinders are offered in two different versions. The 20-500 High Security series which is U.L. 437 Listed and the 20-700 Controlled Access series which offers the same key control protection when U.L. 437 Listed cylinders are not necessary. Both series are fully compatible in application and can be combined into the same masterkey system, along with Schlage standard cylinders. For added flexibility, all Primus cylinders can be retrofitted into existing Schlage locks as well as many competitive products.