Size: 16.5 * 8.8 * 2.3cm Material: Plastic Color: green / dark blue / red / blue 1: Widescreen display meet daily large calculation needs large screen and font to clearly observe the calculation results 2: Acrylic board protection display panel protect the screen not easy to draw 3: Using plastic buttons clear numbers comfortable not easy to wear 4: Power supply with the button battery sufficient electricity long service life 5: Sliding the cover the cover can be split up and down is overwhelming 6: With a variety of functions functions standard difference coordinate conversion data editing continuous calculation memory function error correction function etc.