Ultra-Violet Sterilizer add-on kit provides 100% protection against bacteria, viruses, cysts and pathogens in the product water. Great for well or surface water sources. Ensures the safest water. Includes UV unit with 1/4 in quick connect fittings, 3/8 in quick connect elbow fittings, clips and transformer. For use with Small Boyƒ?›, Evolution RO1000ƒ?›, Merlin Garden Pro and any other filter systems with 1/4 in and 3/8 in fittings and up to 1 GPM flow rates.