All metal powder coated case
The advantage of Perma-Cal® direct drive over conventional C- tube gauges is simple, there is only one moving part No gears, linkages, or springs to wear or break. Perma-Cal® gauges have a unique helical-wound elastic element that is attached directly to the pointer shaft. This eliminates the need for any movement-amplifying gears or linkages (the parts of a C-tube that fail most frequently). Perma-Cal® gauges maintain their structural integrity and accurate calibration in the most demanding environments, even during prolonged and rugged use. Perma-Cal® direct drive pressure gauges provide the lowest cost of ownership by giving the best value in durability, reliability, and accuracy.