Bring more credential flexibility to the door without complicating the installation. The HID Global SIGNO20K mullion reader combines 13.56 MHz and 125 kHz support with keypad input, giving security teams a single device that can serve legacy badges, current smart credentials, and PIN-based workflows. OSDP and Wiegand connectivity make it easier to fit into both modern and existing access control architectures. That matters when you are upgrading in phases, standardizing across multiple sites, or preserving controller compatibility while improving the reader layer. The mullion form factor is well suited to narrow door frames and retrofit projects where space is limited. Mobile reader support adds another layer of credential flexibility for organizations moving toward phone-based access without abandoning card-based operations. For buyers, this is the kind of reader that earns its place by reducing future replacement pressure and supporting a broader access strategy from day one.