Futaba 4PM + 4-Channel 2.4GHz T-FHSS Radio System R304SB Receiver FUT01004416-3 Published by admin on December 17, 2023 This combo includes an R304SB receiver. R304SB and R304SB-E are not compatible with SR system. GYRO MIXING (GYRO MIX): The sensitivity of Futaba car rate gyros can be adjusted from the T4PM.