Sanwa Airtronics RX-471W 4-Channel 2.4GHz 3.7V~7.4V Waterproof Receiver

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)