12-digit heavy-duty printing calculator features an extra-large fluorescent tube display and a high-speed two-color ribbon printing. Print 4.8 lines per second with positive numbers in black and negative numbers in red. Plain paper roll is 2-1/4 (57mm) wide. Quick reference guide briefs you on main functions or address book information. Functions include time calculation average one-touch tax calculation clock/calendar cost/sell/margin calculation sign change item count memory grand total round-up/off/down shift key and 0 00 000 keys. Decimal point positions include add mode 0 2 3 4 6 and floating. Calculator runs on AC power and shuts off automatically after seven minutes.