Check the listing for details. Checkerboard Optical Lens Diffuse ~ No Reflection Alumina Calibration Plate 5 *7. Condition: New. Listed at 24.85 USD. Offered is a 5 x 7 (board size is 215 mm * 215 mm) 30 mm, rounded cornered, very high-quality, checker calibration plate. This calibration plate was purchased new about 6 months ago, only to sit in its sealed bag since. Your calibration plate will be thoughtfully packaged by an industry professional. It will then be shipped promptly, (fast and free) from the USA, on the same day that payment is received. International buyers are also welcomed. Check out my feedback rating to purchase with confidence! Side Note. The following are awesome deals on some of my other calibration related listing:A new, square corner alumina calibration plate can be found at this eBay listing.New, unopened Spydercheckr 24 calibration kits can be found at this eBay listing.A bundle of Colorcheckr Pro plates plus a Spydercheckr 24 can be found at this eBay listing.