This vintage Texas Instruments TI-1000 Five Function Calculator is a rare find, complete with its original box. Its medium-sized keys and handheld size make it convenient for on-the-go use, and operates with a 9V battery power source. The calculator has been thoroughly tested and is in working condition. In addition, this calculator boasts a classic design, dating back to 1977, that is sure to appeal to vintage electronics enthusiasts. The calculator is a great addition to any collection, and its United States manufacture only adds to its value. Purchase with confidence, as this product has been carefully inspected and is sure to meet your needs.