"It is using a HXT 9gram servo for pitch, and a HS85MG for roll. Essentially, I built a basswood cradle that fits the GoPro snug and then created a pivoting system around it. The cradle is reinforced with .5oz fiberglass cloth and thin CA. There are two Dubro 4-40 ball links that screw into 4-40 blind nuts installed in the cradle. The 4-40 ball links are the pivoting point for the pitch axis. I don't get a whole lot of pitch movement, but that can be changed easily if I want to. The whole system without the camera weights less than 3oz (just a guess, it might be less!)."
gimbal from diydrones.