The Texas Instruments TI-89 Graphing Calculator with Cover is a handheld unit powered by batteries, featuring a regular display size and key size. It comes with advanced graphing capabilities and a durable hard slide-cover included. This graphing calculator is officially approved for use in the SAT, PSAT, and AP exams, making it ideal for students and professionals alike. The unit also includes Pretty Print Technology to display complex mathematical expressions and a Computer Algebra System (CAS) for solving equations. With a high-resolution 100 x 160 pixel LCD screen, this Texas Instruments TI-89 calculator offers reliable performance for various tasks.