The Von Duprin 48009456 is the OEM ALK (Alarm Kit) cover plate kit for the Von Duprin 78 Wide Stile exit device in the 70 Series. It fits both 3-foot and 4-foot device lengths. Finish must be specified at time of order. Per the Von Duprin 70 Series Parts Manual (doc 116131), the 48009456 is specifically for new ALK exit alarm kits manufactured after July 2021 - if the installed ALK predates that manufacturing date, a different cover plate applies. Confirm the ALK production date before ordering.

The 48009456 covers the ALK mounting position on the 78 push bar when the alarm kit has been removed, repositioned, or reconfigured. It is a different component from the 48009455 (fire or less dogging cover plate) - those cover the dogging slot; the 48009456 covers the ALK slot.

What the Von Duprin ALK Is

ALK stands for Alarm Kit - Von Duprin's internal horn alarm option for the 70 Series exit devices. Per the official Von Duprin ALK product description: "The Von Duprin alarm kit is a simple yet effective way to deter unauthorized use of an exit. While the exit device is still a means of egress, the alarm kit contains an internal horn. When the touch bar is depressed, the horn sounds to provide an audible signal that the opening has been activated."

The ALK operates on 24VDC with External Inhibit included as standard. External Inhibit allows remote arming and disarming of the alarm from an access control panel or security console without using the key on the device itself. The alarm automatically re-arms after the door closes based on configurable time delays: 1.5 minutes, 3 minutes, or 4.5 minutes. A low battery condition is flagged through an intermittent horn alert before the battery fails. The ALK ships with a 6" x 20" door decal reading "EMERGENCY EXIT ONLY. ALARM WILL SOUND."

Von Duprin Cover Plate Kit: Why the ALK Slot Needs to Be Covered

The ALK mounts in a specific position on the 78 Wide Stile push bar - typically on the strike side, in the same area where hex dogging hardware would otherwise be located. This is not a coincidence. Per the Von Duprin 70 Series Exit Device Selection Guide (doc 116047): "When the ALK is used, standard dogging is removed." The ALK and hex dogging occupy the same mounting position on the device and cannot coexist at that location.

When an ALK is removed from a 78 device - whether because the alarm function is being decommissioned, the device is being reconfigured, or the ALK is being moved to the hinge side to make room for cylinder dogging on the strike side - the mounting slot left by the removed ALK is open on the push bar. The 48009456 cover plate kit closes that opening with a finished plate that matches the device finish, restoring a clean professional appearance and preventing access to the internal push bar cavity.

Von Duprin ALK Cover Plate Kit: Post-July 2021 Format Requirement

The Von Duprin 70 Series Parts Manual explicitly notes that the 48009456 cover plate kit applies to "new ALK exit alarm kits manufactured after July 2021." Allegion updated the ALK design in July 2021, and the new-format ALK uses a different mounting interface than the legacy version. The 48009456 cover plate is sized and configured for the new-format mounting dimensions. A legacy ALK installed before that date requires a different cover plate. Check the device's manufacturing label or the ALK unit itself to confirm the production date before ordering.