The top plate has integrated Z-Rail (NATO rail) for quick mounting rail based top handles, arms, monitor mounts, etc. It has a flush top for mounting other accessories across it plus 1/4" 20 and Arri style 3/8" 16 threaded holes on top and sides. There is also a provision for mounting two 15mm rod locks (additional) for rods to support focus motors and other top mounted rod accessories.