This document introduces the usage conditions and specifications of the Futaba R6303SB high-speed receiver. The high-speed mode only accepts digital servos, and connecting an analog servo may cause a malfunction. If a malfunction occurs, the receiver should be changed back to normal mode. The receiver complies with part 15 of the FCC rules, and features dual antenna diversity and an S.BUS port. It is lightweight and compact, making it suitable for various systems.