Eureka! Quickly and accurately measure an object's mass and volume-with one apparatus! How is this possible? This unique balance utilizes Archimedes' principle of fluid displacement and buoyancy force-the same principle used to explain why a 500-ton battleship floats on water. Use this device to measure the mass and volume of solids and liquids, and then calculate their densities. Comes complete with plastic, 100-mL graduated cylinders with end caps and bases, plastic inner flotation tubes with end caps, and an instruction manual. Square flotation tube is 18 mm x 18 mm x 195 mm. Works great with Specific Gravity Metal Specimen Set (AP9234) and the Equal Mass Kit (AP4636).