ETA hand2mind Plastic Fillable 3D Shapes, Clear Geometric Solids for Measuring Volume (Set of 6) Visually demonstrate that different geometric solids can have equal volumes Unique collection features clear plastic solids that can be filled with liquids, sand, or rice Incorporate measurement, mass, and spatial awareness into any teaching lesson Shapes measure 3-4" inches Set of 6 shapes includes a cone, sphere, cylinder, pyramid, cube, and rectangular prism