High density quality material: non-, safe, and reliable, with a purity of up to 99.6%. vacuum packaged to maintain a natural appearance and prevent oxidation. Laser engraving: Each Square is engraved with chemical symbols, name, atomic number, density, purity, atomic mass, melting point, and electronic layer structure, with clear edges, flat cutting, and a minimum market tolerance of (+/-0.1) mm. Widely used: Metal Squares can be used in laboratories, offices, science rooms, teachers, gifts, scientific demonstrations, suitable for different ages, with a good understanding of metals, elements, and densities. They can be placed in the classroom to stimulate students' interest. Chemistry can be collected as artwork. : This product can not only be used for collection, but also as a family and friends. It is suitable as a birthday gift, graduation gift, , wedding gift, and other occasions. Colour: Material:aluminum Size:2.54cm Package Contents: 1 x Square