All ULTRAMAX ET series "Liquifix" batteries use AGM technology which consists of an Absorbent Glass-fibre Matting between the lead plates inside the battery. Replaces the following Part Numbers: 509 901 020, FTZ12S-BS, YTZ12S, YTZ12S-BS, PTZ12S-BS, ETZ12S-BS, GTZ12S-BS, CTZ12S-BS.
