This is an Sanwa/Airtronics RX-371W/92621 3-Channel 2.4G FHSS-2 Waterproof Receiver. The new RX-371W is a small lightweight receiver that is compatible with all Airtronics 2.4G FHSS-2 frequency modulation surface transmitters. This receiver is waterproof and works equally well in cars, trucks and boats, and is a great way to go if you don't need more than three channels. The receiver has a nominal input voltage up to 7.4 volts, so you can power the receiver with a 2S LiPoly battery and use high-voltage servos.
Frequency: 2.4GHz FHSS2
Power supply: 4.8~7.4V