The front hinges (also called arm pivot shafts, hinge pins, or hinge axes) for the DJI Matrice 4T are small metal pivot components used at the joints where the front motor arms connect to the drone’s main fuselage. They allow each front arm to fold in for transport and unfold/lock securely into the correct position during flight. These pins enable the folding arm mechanism that’s central to the Matrice 4T’s design.