Set of 12 cylindrical bars in a variety of materials for identification exercises and exploration of density mass and volume. Each cylinder is the same diameter (12.5mm) but each has a different length. A complete manual is included that describes the basics of density mass and volume and instructions for making calculations.Materials included:HardwoodSoftwoodAluminiumCopperBrassRubberNylonDerlinPVCGlassAcrylicTeflonAll contained in a wooden storage block.Please note: Due to the nature of some of the raw metals some oxidation or corrosion may occur due to humidity and storage. Simply scuff off any oxidation to make them look new again. Designed for use in an educational setting.