External Signaling with the RY-AC/A Relay on the LEF Series Updated on March 30th, 2026 How to use the RY-AC/A External Signaling Relay with the LEF Series. External Signaling with the RY-AC/A Relay on the LEF Series LEF Series Door Release Wiring LEF Series General Installation and Operation Guide LEF Series Volume Control LEF Series with 8-Ohm Speaker