This is the Sanwa RX-471W 2.4Ghz FHSS-4 Waterproof 4-Channel Receiver. The RX-471W Super Response waterproof receiver is compatible with Sanwa/Airtronics 2.4GHz FH3 and FH4T transmitters, such as the M12, MT-4S, MT-4, MX-3X, M11X, EXZES X and others. This 4-channel receiver features an extremely low latency time and high frame rate, which makes you feel more connected to your model than ever. Combined with Sanwa's specially made Super Response servos, the RX-471W Super Response receiver will give you reaction speeds like never before!

Features: 

• Compatible with all Sanwa and Airtronics 2.4GHz FH3 and FH4T Surface Transmitters
• Waterproof (IPX4 Spec)
• Extremely Low Latency Time and High Frame Rate
• Compatible with Sanwa Super Response Servos
• High Voltage - Compatible with 2S Li-Po Receiver Battery
• Small and Lightweight
• Finger Accessible Bind Button
• Supports Receiver Battery Fail Safe Monitoring

Specifications: 
Model: RX-471W 
Frequency: 2.4GHz FH3/FH4 (Selectable Via Transmitter) 
Nominal Input Voltage: 4.8 to 7.4 Volts 
Dimensions: 1.18 x 0.91 x 0.55 Inches (30.0 x 23.3 x 14.0mm) 
Weight: 0.35 Ounces (10.1g) 
Battery Fail Safe Limit: 3.5 to 5.0 Volts (FH3) / 3.5 to 7.4 Volts (FH4)

NOTE: This receiver is not compatible with Sanwa aircraft transmitters or FH2 surface transmitters.