AMZBD Fish Tank Filter Cartridge for Top Fin Cartridges,PF-L Aquarium Filter Cartridges,Replacement Filter Cartridge for TOP FIN PF20,PF30,PF40 & PF75 Power Filters(15pack)Brand: AMZBD Features: Top Fin Compatible Filter CartridgeThis filter cartridge is suitable for Top Fin filter and perfectly matches Top Fin PF20,PF30,PF40 and PF75 Power Filters. The specific dimensions of the filter element are 6 in L x 4. 5 in W inches. With this aquarium filter cartridge, you can always maintain healthy water quality. Excellent Filtration PerformanceAfter many scientific tests, the high quality cotton and activated carbon