Heavy-duty calculator prints 4.6 lines per second in two colors. Design features an extra-large 12-digit fluorescent display and built-in metal paper holder. Cost-sell-margin keys allow you to quickly and easily solve cost-sell-margin problems by entering two variables, and the third appears and prints. Other functions include time/date feature, two independent tax keys, four-key memory, Sigma, percent, delta percent of change, backspace key, grand total, automatic constants, change sign key and item count with averaging. Calculator runs on AC power and weighs 3.5 lb.