OASE Filtoclear/BioPress/Bitron 9 Quartz Sleeve
This UV Quartz Sleeve (13312) installs horizontally in the filter lid and fits:
BioPress 1600
FiltoClear 800 (56152)
FiltoClear 1600 (56151)
FiltoClear 3000 (56150) First Generation
FiltoClear 4000 (56932) First Generation
Bitron 9 UVC