The 3B Scientific U21850 vacuum experiment plate for assembling a vacuum chamber with a bell jar (sold separately) is used to demonstrate physical phenomena in coarse and fine vacuum ranges. The metal plate is mounted on a tripod for stability and topped with a rubber disc to provide an effective vacuum chamber seal. Its central bore hole has M12 thread for securing experimental equipment. It has two ports for attaching a vacuum hose and ventilation. Two 1m cables with 4mm safety plugs connect to a maximum 48V, 12 amp power supply (sold separately). The plate measures 250mm in diameter and 90mm high. Science education products incorporate applied math and science principles into classroom and homeschool-based projects. Teachers in pre-K, elementary, and secondary classrooms use science education kits and products alongside science, technology, engineering, and math (STEM) curriculum to demonstrate STEM concepts and real-world applications through hands-on activities. Science education projects include a broad range of activities, such as practical experiments in engineering, aeronautics, robotics, energy, chemistry, physics, biology, and geology.3B Scientific manufactures anatomical models, simulators, charts, and other training materials for use in scientific, medical, and patient education. The company, founded in 1948 and headquartered in Hamburg, Germany, meets International Organization of Standardization (ISO) standard 9001: 2008.What's in the Box?