This is a companion part to the Alexmos Controller Board Box. It houses the Alexmos 3rd Axis Controller and piggy backs onto the 2 axis controller box, replacing the back cover. An M3 x .5 tap is required to put machine screw threads into the cover that replaces the back of the Alexmos board box. Four screws required to hold together. Two M3 14mm long and two M3 24mm long. Only for boards that are identical to, or available through here http://flyduino.net/Alex-Mos-Brushless-Gimbal-BLG_3 or here https://viacopter.eu/multirotor-shop/camera-gimbals/alexmos-brushless-gimbal-controller-3rd-axis-extension-board-multicopter-store. ----------------- New version uploaded 18-SEP-2013 text labeling has been added for pinout of the yaw motor. -----------------Update 19-SEP-2013 - Moved feature on motor pinout to correct alingment.