Norton 8146689 Narrow Top Rail Drop Plate is designed for concealed door holder applications on the 8000 Series aluminum finish door closers. This plate is essential when a narrow top rail (between 1-9/16" and 2-7/16" for Series 8000, or 1-7/16" and 2-5/16" for Series 8080) prevents direct mounting of the closer to the door surface. Compatible with regular arm installations, it meets ANSI/BHMA A156.4 Grade 1 standards and comes backed by a limited 25-year warranty, ensuring dependable commercial-grade performance and longevity.