12-Digit Large Display Water-Protected and Dust-Proof Calculator. Revolutionary new design featuring a detachable, washable keypad. Suitable for use even in demanding enviroments. No need to worry about exposure to water, dust, or grime. It is recommended for use even at open-air markets, street stalls, and other outdoor businesses and at shops that sell fresh food. Solar power with battery back up. Key Rollover. IP54-compliant water-resistance and dust-resistance. Percentage Calculation incl. Profit Margin. Profit Calculation (Cost, Sell, Margin). Tax-Calculation. 3-Key Memory. 3 Digit Comma Markers. Key for changing Plus/Minus Sign. Double Zero Key Color: Yellow.