Easy to use, large display: All products with batteries have passed the test,caution! ! ! Be sure to install the battery to use It install batteries to avoid unpredictable errors, one BATTERY of this product,12 digits, better field of view, corners of the eyes, upright LCD screen; automatic shutdown (not used for 10 minutes). Non-slip design: Non-slip washers are not easy to slide during operation. Durable silicone button: good sense of touch, ABS plastic material, Light weight. Reasonable configuration and comfortable operation. Solar and Battery Dual Power: Solar and backup batteries keep the desktop calculator working in low light conditions. The calculator can handle solar energy, 1.5v battery as battery backup and have automatic power supply.(Batteries not included) size: 12*15CM