AquaTop Replacement 9W UV Bulb Square Base 2 Pin AquaTop UVE9 Submersible 9 Watt UV Sterilizer AquaTop CF400 Canister Filter w/ 9 Watt UV Sterilizer AquaTop CF500 Canister Filter w/ 9 Watt UV Sterilizer AquaTop UVCP-9 Submersible UV Sterilizer, 9W