This TI-36X Pro Calculator by Texas Instruments is a reliable and efficient tool for all your mathematical needs. With its regular-sized display and handheld size, it's perfect for on-the-go calculations. The calculator runs on solar power and is equipped with a variety of functions, making it a great choice for students, engineers, and business professionals alike.

This calculator is categorized under Business & Industrial, Office, Office Equipment, and Calculators. It's a scientific calculator with a regular key size, and its brand is Texas Instruments. The model is Pro Scientific TI-36X. Please note that this calculator works perfectly but needs a new battery.