This Sienna Plein Air quick release plate for Sienna tripod easel. Artists may find that it is useful to have extra quick release plates for multiple pochade boxes, or keep an extra one as spare partTo mount the Sienna pochade box on Sienna plein air tripod ball headTripod should come with a ball head where this quick release plate fitReplace lost of quick release plate or keep an extra one as spare partThe screw size is a standard 1/4 inch size fits most of camera tripodDimensions Length 5 inches, Width 3 inches, Depth 1/2 inch