The Texas Instruments TI 83 and TI 83 Plus are handheld scientific and graphing calculators with a regular-sized LCD display. They are powered by batteries and feature advanced functions such as calculus, programming capabilities, and a wide range of graphing functions. These calculators are ideal for students and professionals in various fields who require precise calculations and graphing capabilities on-the-go. Please note that these units are being sold for parts only, but they still hold value for those in need of specific components or interested in repairing similar calculators.