The RainSoft Ultrefiner Compatible CTA RS9-10 RO Membrane is a 10 gallon per day CTA (Cellulose Triacetate) membrane that replaces parts 17376, 21173, and M-C1810R10. This membrane is used in Rainsoft Reverse Osmosis Systems 9590, 9593, UF-10, 9594, 21173 and some other Rainsoft models. CTA membranes are best for Chlorinated water.
Dimensions: 1 1/2" x 10"