A filter cartridge, a safety element and fluid cleaner assembly are described. The fluid cleaner assembly generally includes a housing having a cover and a primary fluid cleaner section. The filter cartridge generally comprises z-filter media, arranged in a straight through configuration. Preferred cartridges include a seal gasket positioned to extend continuously around at outer perimeter of the straight through flow construction. The fluid cleaner assembly can have a precleaner positioned therein. Preferred features are described. Methods of assembly and use are also provided.