This is the Ace RC TRS403ss 4-Channel 2.4GHz Mini Receiver.

FEATURES: Ideal for helicopter, car and boat use
          Easy one-touch binding
          Single antenna

INCLUDES: TRS403ss 4-Channel 2.4GHz Mini Receiver

SPECS:    Battery Power: 4.8-6.0V
          Dimensions: 1.40 x 0.72 x 0.56" (35.6 x 18.3 x 14.2mm)
          Weight: 0.23oz (6.5g)
          Data Mode: iFHSS

                                                                   jxs 05/07/13
                                                                         ir/jxs