ZenBlue CUV-218 Pond and Aquarium UV Sterilizer Filter Maximum Flow Rate of 3170GPH Includes 3 Inlets/Outlets (One in/Two out or One in/One out) Easy Unscrew-release for Bulb/Quartz Maintenance Perfect fit with CBF Series Box Filters; Clarifier with 18w UV Bulb Included Compatible with CBF-350 & CBF350B Mechanical ZenBlue 1 Year Warranty (Bulb not covered in warranty)