Calculate grand totals for sales without a computer. Clock and calendar function makes it easy to keep track of the time and date of each receipt—prints alongside each sale. Profit margin function allows you to compare the differences between sales and maintain records from month to month. Low-battery indicator keeps you aware of your power status. Time calculation option enables time-based fee structures. Power Source(s): AC; Battery; Display Notation: Numeric; Number of Display Digits: 12; Display Characters x Display Lines: 12 x 1.