RavTech(TM)4Pcs 300g FPV Gimbal Vibration Damping Balls for Gimbals Gopro DJI Quadcopter Aerial Photograpy 100% brand new Mounting: 7mm hole or bolt threw. Isolation rating: 300g per ball. 4 * 300g FPV Vibration Damping Balls Search RavTech for more choices!