Key Features Genuine Oase Part Part No 12090 Fits BioSmart Filter Units Easy to replace Ideal to replace lost or damaged parts Genuine Oase Replacement Quartz Sleeve Nut set. This replacement fits the Biosmart 5000 - 16000 (please refer to filter instruction manual for part numbers) The Set consists of screwed nut with O ring for fitting at the end of the UVC unit inside the filter. Part No 12090 Fits Biosmart 5000 (50525) Biosmart 7000 (50449) Biosmart 8000 (57375) Biosmart 14000 (50451) Biosmart 16000 (57377) MultiClear 5000 (50293/50238) MultiClear 8000 (50294/50239)