SmallRig Magic Arm 2115 includes two ballheads on the ends, with one ballhead with Arri locating pins and the other ballhead with a 1/4" screw. Ballhead with Arri locating pins is compatible with camera cage or monitor cage with Arri locating points. It prevents magic arm from twisting, thus it increases the stability and security of magic arm. It comes with a thumb screw to lock the cage tight manually, or even tighter with the use of the hex spanner. Ballhead with a 1/4" screw is compatible with camera cage or monitor directly. It could attach the side or top of camera cage on the one end and attach monitor on the other end. Two ballheads comes with rubber cushions could increase the friction between ballhead and ballhead clamp, thus ensuring firm locking.