The Crestron C2COM-3 was a Y-bus expansion card designed to add three serial communication ports to compatible 2-Series Crestron control systems like the AV2, PRO2, and RACK2. Each of the three ports (DB9 male connectors labeled A, B, and C) supports bi-directional RS-232, RS-422, or RS-485 serial communications, allowing integration with a wide variety of third-party devices. The card was built to fit into an available Y-bus slot in the control system's chassis and featured baud rates up to 115.2k with hardware and software handshaking. The C2COM-3 was essential for expanding a control system's capabilities by enabling it to communicate with and control non-networked equipment. This product has since been discontinued, with newer 3-Series and higher systems using different card formats.