Professional Calculator features a 12-digit, large, easy-to-read display as well as two-color printing & display & tax & exchange functions. The two-color ink ribbon printer prints 3.5 lines per second. Offers built-in tax & exchange function. Full decimal system: floating, fixed (0-6) with round-off, round-up or cut-off, & ADD mode. Mark-up / down key. Right shift key for quick correction. Independent memory. AC operation.