BlueNote: all new TI-84 Plus calculators from Texas Instruments come with a plastic cover. Please purchase our product with this in mind. Thank you for shopping! slide cases are the only patented slide cover on the market that offers functionality to a calculator cover. Say 'hello' to beautiful lines with the slide case for the TI-84 (all models) and TI-89 Titanium Calculator. Keep a straight edge wherever you bring your calculator! Featuring a 6 inch side ruler, a 6 centimeter top ruler, an XY axis template that will cut down time graphing axes and 12 Math functions that are important for any mathematician (middle school to college). Not only can the XY axis template help you graph, but it can draw perfect rectangles, 3-4-5 right triangles, isosceles triangles, parallel lines and much much more. Great for Geometry, Algebra, Precalculus and Calculus classes. Please visit product features tab at the ezgraphing website for geometry directions. Every slide case is Made in the USA!