Introducing the Donaldson safety air filter, a reliable backup in case of primary filter damage or improper installation. Measuring at a substantial 20.66 inches in length, with an inside diameter of 7.06 inches and an outside diameter of 8.65 inches, it's designed to ensure contaminants stay clear of the clean side during primary filter servicing. Engineered for swift response, this filter plugs promptly if any contamination bypasses the primary filter, alerting operators promptly. In adherence to ISO 5011 standards, we recommend replacing safety filters with every third primary filter change, unless there's been a primary filter failure.