Portable printing calculator features a 12-digit LCD screen and prints 2.0 lines per second. Functions include tax +/- keys, three-key independent memory keys, cost/sell/margin keys, backspace key, date/nonadd, percent key and automatic constants. Design offers a swing-out paper arm to hold standard 2-1/4 wide paper. Calculator offers AC/DC operation with the included AC adapter. The required four AA batteries are not included. Calculator automatically shuts off after six minutes."