About the 11w Single-Ended UVC Bulb - BOGOF Manufacturer: UVC Bulbs ADD ONE 11W BULB TO YOUR BASKET AND RECEIVE TWO!!! This single-ended UV bulb fits many popular filters such as the following*: All-in-OnesOase Filtral 9000PondXpert TripleAction 4500 EvolvePondXpert TripleAction 6000 Evolve FiltersHozelock Bioforce 8000Oase Filtoclear 6000Oase Filtoclear 11000Oase Filtoclear 15000Oase Filtomatic Intelligent 7000PondXpert EasyFilter 12000PondXpert SpinClean 4500PondXpert SpinClean 6000 (Older Model)PondXpert SpinClean 12000 (Pre-2019 model)PondXpert SpinClean Auto 4500PondXpert SpinClean Auto 5000PondXpert SpinClean Auto 6000 UVCsHozelock Vorton 11PondXpert Greenstop 9000 * THESE BULBS DO NOT FIT THE HOZELOCK EASYCLEAR 7500 - PLEASE CALL US ON 01642 370888 FOR MORE INFORMATION.