HQUAOWS-6L 25W Germicidal Tube, 4-Pin Base, Water Purifier Replacement Source for 6 GPM Water Disinfection System, 2 Pack

I treat my well water with this UV light bulb and replace it every year. The bulb still looks very bright after a year of continuous use, but its recommended replacement is every year. I test my pre and post bulb well water every year. The pre bulb water always tests positive for coliform (low levels but with warnings) The post treated water tests "unmeasurable" for coliform. I've convinced neighbors to use the same system.

I was satisfied with the water filter tube. It arrived in good time and is exactly as I hoped.

Perfect fit