R7WUV-SQ 7 Watt UV Replacement Bulb: AQUATOP 7 Watt UV replacement bulb compatible with the following AQUATOP products: FZ7 Canister Filter With UV Sterilization PFUV-25 Hang-On Filter With UV Sterilization PFUV-40 Hang-On Filter With UV Sterilization UV Sterilizing Pump - SP7UV UVE Sterilizing Pump - UVE-7 R13WUV-SQ 13 Watt UV Replacement Bulb: AQUATOP 13 Watt UV replacement bulb compatible with the following AQUATOP products: FZ13 Canister Filter with UV Sterilizer SP13-UV Internal Filter with UV Sterilizer UVP-13 Submersible Pump UV Sterilizer UVCP-13 Submersible Pump UV Sterilizer UVFK-13 Submersible Pond UV Sterilizer with Pump + Fountain Kit UV Sterilizing Pump UVE13.