This square boss head clamp is die-casted from alloy with metal clamping screws. It accommodates both square and round rods up to 16mm in thickness at right angles to each other. The clamp can also hold flat articles such as rulers, magnets, and drawing boards up to 16mm thick. The clamp measures approximately 5.5 x 5.5 x 5cm. Its versatile design makes it a practical component for retort stand assemblies in science classrooms and laboratories.