This is the SR-10 Dual Servo Reverser from Futaba.
      This is used to "Y" two servos, on one channel on your receiver.
   The Dual Servo Reverser will enable both servos to move as they should, by
             switching the movement of one of the servos.

FEATURES: Perfect for use on large-scale aircraft that require two servos on
            one control surface.
          Delivers precision control without the need for special mixing
            from the transmitter.
          The center pot centers on the servo reverser centers both servos
          Along with an RF noise filter that eliminates interference.

INCLUDES: One Dual Servo Reverser
          One adjustment Screwdriver
          Instructions

REQUIRES: Installing in your plane, car or boat.

SPECS:    Length: 26" from Rx plug to servo plug
          Case: Width:  23mm
                Length: 38mm
                Height: 9.2mm
                Weight: .9 ounces (25.5 grams)

COMMENTS: A super accessory for dual elevator servos, dual flaps and twin-
            engine models- as well as in conjunction with Futaba's new
            GYA aircraft gyros.

          This will work on digital as well as analog servos.    10-23-01
                                                            updated jpg 4/18/06