Water columns in mm are a measurement of water-resistance, mostly for leisure and outdoor clothing. It describes the water pressure required to let water through a material. The tests to determine the water columns in mm are carried out when the material is in new condition, which is why this information is not especially meaningful for work clothing. In order to meet the specific requirements of the world of work, it is necessary to include the durability and lifespan, as well as water-resistance under mechanical influence. Engelbert Strauss weather-protective clothing is therefore certified in accordance with DIN EN 343:2003. Simulated snapshots provide information about the water-resistance of a product. For example, a jacket is first treated with oil or other residues found in the world of work, or exposed to increased mechanical strain, in order to test water-resistance in this state. If the stitching and material withstand the water pressure, the product complies with DIN EN 343: 2003. The higher the standard category (1, 2 and 3), the longer the item is required to withstand the water pressure. When it comes to information based on the water columns, we consciously avoid assuming that this measurement alone provides information about water resistance and breathability under mechanical stress. Only the combination of functional features (water-resistance/breathability) and mechanical properties (durability/stability/lifespan/robustness) ensure maximum performance for wearers of protective work clothing.