Basic Desktop Blue Tax calculation Profit calculation 12 digits LCD Battery/Solar LR54 Tax calculationAutomatic calculation of price plus tax, price less tax, discount, selling price, tax amount, discount amount, and margin amount.Time calculationTime calculation allows easy input and calculation of hour, minute, and second values.Two-way power (Solar + Battery)Solar powered when light is sufficient, battery powered when light is insufficient.Function command signsA symbol (+, -, ×, ÷) on the display indicates the status of operation you are currently performing.Key rolloverKey operations are stored in a buffer, so nothing is lost even during high-speed input.Extra Large displayLarger display makes more data easier to read.Plastic keysDesigned and engineered for easy operation.Profit margin percent" % " key gives quick access to prices and profits, and also delivers add-ons, discounts, ratios and increase/decrease values. Design Non-slip feet Yes Keys quantity 29 keys Control type Butt