From the beginning, the Rex calibrator was designed to be simple to use. Unlike a conventional scale, it doesn't require the fabrication on an exotic fixture to hold the gauge, and the user doesn't have to perform any complicated calculations to determine if a gauge is in calibration. With the RDC-1, simply secure the gauge in the clamp and slide the weight to the appropriate point on the scale, if the gauge reads within +/-1 of the point indicated on the scale, it's in calibration. The RDC-1 offers quality unparalleled by any other. With its thick steel base, oversize stainless steel column, and thirty pound weight, the RDC-1 is the sturdiest calibrator made. All components are precision CNC machined to exacting tolerances, and then plated or painted to insure long life. The RDC-1 comes to you fully calibrated with documentation traceable to NIST. It also comes with instructions and technical notes covering specifics about durometer calibration. The Rex RDC-1 calibrator is made and assembled in the U.S.A