The 90 degree Dual Side Mount B brackets allow you to easily attach the ¼ scale servo plate A to the end or top of the Actobotics Channel. The brackets have (4) 6-32 tapped holes; 2 to mount the servo plate to the bracket and 2 to mount the bracket to the channel. When the 90 degree dual side mounts are used in conjunction with the ¼ scale servo plate A, it perfectly aligns the spline of a Hitec ¼ scale servo with the ½” bore of the channel.