Beach RC says... Sanwa RX-472 2.4GHz 4-Channel FH4T Super Response Receiver, with (SSL). RX-472 features a low latency time and high frame rate, which makes you feel more connected. 

Features:

• Sanwa Synchronized Lik (SSL) Compatible
• Designed for Use with Artronics M12, MT4S, and Sanwa Exzes-Z Transmitters and Sanwa Super Vortex Zero ESC*
• Extremely Low Latency Time and High Frame Rate
• Compatible with Sanwa Super Response Servos
• Compatible with 2S Li-Po Receiver Battery, So You Can Use High Voltage Servos Without a Voltage Regulator
• Small and Lightweight
• Finger Accessible Bind Button
• Supports Receiver Battery Fail Safe Monitoring

Specifications:
Model: RX-472 (92015)
Frequency: 2.4GHz FH3/FH4T (Selectable Via Transmitter)
Nominal Input Voltage: 3.7 to 7.4 Volts
Dimensions: 1.18x0.91x0.55" (30.0x23.3x14.0mm)
Weight: 0.23 Ounces (6.6g)
Battery Fail Safe Limit: 3.5 to 5.0 Volts (FH3) / 3.5 to 7.4 Volts (FH4T)