Square Boss Head Clamp Die Cast Alloy up to 16mm Rods at right angles to each other.Die casted alloy clamp with metal clamping screwsAccommodates both square and round rods up to 16mm in thicknessCan also be used to hold flat articles such as rulers magnets drawing boards etc. up to 16mmDimensions: 5.5 x 5.5 x 5 cm