The Precision Combo Calibration Device (p/n 100-27-31) includes a 4mm calibration ball for spherical calibration and a mounted pin for horizontal and vertical calibrations with any version of DROPimage. The uncertified product (100-27-31-U) ships by itself without a calibration report; the certified product (100-27-31-C) ships with a detailed certified calibration report that is NIST / ANSI traceable, and contains the results of a series of water contact angle measurements using pure deionized water. This reference tool may be used with any ramé-hart contact angle goniometer (including legacy systems). If you wish to have your existing Certified Precision Combo Calibration Device recalibrated choose recalibrate, (p/n 100-27-31-RE). This will require that you ship to us your existing device and a copy of the original Certificate.