The Texas Instrument TI-55-ii Scientific Calculator is a handheld unit perfect for any office or academic setting. With regular key size and display size, this calculator is easy to use and read. Powered by batteries, it is always ready to go when you need it.Made by Texas Instruments in the United States, this calculator is a reliable and high-quality option for any professional or student. It comes with a carrying case for added protection and convenience. The model TI-55-ii is a trusted and popular choice among scientific calculators.