Oase Biostyle Hang-On Filter 180Product Description If a conventional external filter and an internal filter are not suitable, the OASE BioStyle hang on filter stands out with its own advantages: In comparison to a classic external filter, no hoses need to be laid during commissioning. A cabinet with the appropriate space for positioning the filter is also not re quired here, and the hang on filter does not take up any space inside the aquarium. The BioStyle filter offers a clear