Futaba R304SB 4-Channel T-FHSS Receiver (S.Bus2). Part number FUTR304SB. Futaba R304SB 4-channel T-FHSS telemetry receiver with S.Bus2 for surface models; 6.6g, 4.8-7.4V.
For surface models. Futaba part number 01102179-3.
Note: Use of analog servos may cause servo trouble.