This Texas Instruments TI-81 Blue Graphing Calculator has been tested and is ready to help you tackle any mathematical task. With a battery-powered source, this handheld calculator is perfect for any business or office setting. The brand is Texas Instruments and the model is TI-81.

The calculator is great for graphing functions and calculating complex equations. It is a useful tool for anyone in the market for a high-quality calculator. Additionally, it is perfect for those in the business and industrial field, as well as those in an office setting.