Top Base Length: 58mm Top Base Width: 57mm Panning Base Diameter: 58mm Height: 26mm Net. Weight: 173g Mounting Thread: UNC3/8" Max Load: 20KG The SUNWAYFOTO DDH-07 panoramic panning clamp is CNC machined from T6061 grade aerospace aluminum alloy with military Type-III hard-anodized. The top square base maximizes the contact area between clamp and plate, which provides photographers a more stable shooting equipment in severe environment, and it's compatible with Canon 1DX, Nikon D4S, D3X etc. professional cameras.