Orpat OT 400T/400GT Calculator (White/Grey) Orpat brings to you this 400T/400GT Basic calculator which comes with standard keys so that you can easily type in your numbers. This basic calculator comes with a plastic casing and is also equipped with an 8 digit display to give you a clear view of all the numbers. In addition, this OT 400T/400GT Basic calculator is powered by a battery to compute all your math problems at high speeds. Add this OT 400T/400GT Basic calculator to your shopping cart and ease the process of calculating all your math problems.