It is a rudder only RC BG for B4-2 or C6-3 motors. There is an article on it in the May/June Sport Rocketry for 2017.
I don't use the Spektrum "brick" radio, but the Turnigy 5X, with the rcvr board out of the case, and put on a plate with an indoor flier tiny servo. Radio system is $25, servo...