The 521P is designed to work with Panasonic cameras AG-DVC30, AG-DVC80, and AG-DVX100A, and enables you to control the record/stop,and zoom in/out functions of the camera. The 521P can be used for a wide variety of applications. It can be mounted to a huge range of supports, such as pipes, bars, tubes, and flat surfaces. CLAMP RANGE: Square tube or flat surfaces: 5mm (0.19 ) - 30mm (1.18 ) height Round tube/pipe/bar: 12mm (0.47 ) - 35mm (1.38 ) diameter Rectangular tube of flat surfaces: 5mm (0.19 ) - 30mm (1.18 ) height