The MDF® Calibra® Pro Sphygmomanometer is designed to be tough under pressure with above industry standard double bellow and ShockGuard™, protecting the gauge against accidental damage. This take on the classic pocket aneroid design features a 20% larger and easy to read dial with high contrast markings, ideal for low light environments. The movement inside each gauge is painstakingly assembled and tested by expert craftsmen, stress-tested 3,000 times and calibrated five times to achieve the highest level of lasting precision.