Yes, this unit has been discontinued as of October 31st, 2019. However, you are still able to purchase parts for this system. It has been replaced with the Hallett 500PN System. This has been linked below for you.
https://www.wahlwater.com/UV-Pure-500PN-Hallett-165GPM-NSF55-Ultra-Violet-Disinfection-System-G15_p_1291.html