Always the correct part
Sanwa RX-391W 2.4Ghz FH-E 3-Channel Receiver. The RX-391W is a waterproof receiver, and is compatible with the Sanwa MX-6 radio system.
NOTE: RX-391W is not compatible with telemetry function.
Frequency: 2.4GHz FH-E
Nominal Input Voltage: 4.8～6.0Ｖ
Weight: 12.7 g
Compatible radio: MX-6