Amazon.com: Seawater RO Membrane Housing for 2.5" x 21" SWRO Membrane | 1200 psi Fiberglass | Replacement Pressure Vessel for WaterMaker | Fits M-S2521A & SW30-2521| PV2521A1200E (For 2.5" x 21" Membrane) :
Membrane Solutions 150 GPD Reverse Osmosis Membrane RO Membrane Housing Kit with 1/4" Quick-Connect, Wrench, Check Valve for Residential Household Hospital Water Filtration System - Walmart.com
Amazon.com: Max Water - Heavy Duty - Reverse Osmosis 4040 Membrane Housing - 4" x 40" good for industrial use - 4040 housing : Tools & Home Improvement
RO Membrane Housing 3013 - for 3013-400, 3013-500, 3013-600 Membrane – Titan Water Pro