Features: 1.Material of the housing:stainless steel 304or316L 2.The material of lid is ABS plastic or stainless steel 3.Membrane housing can be fix 1-4 stage RO membranes. 4.The membrane housing pipe has two types: seam and seamless. 5.Stainless steel,high polished exterior 6.4 end entry,8 end entry,and side entry 7.Smooth and sleek look 8.Unique fro direct connection to most of RO elements 9.Double O-ring 10.Packing:carton model Center length(mm) Total length(mm) Inlet (mm) Outlet (mm) 4021 600 540 Dn15 Dn15 4040-1 1090 1030 Dn20 Dn15 4040-2 2106 2046 Dn20 Dn15 4040-3 3122 3062 Dn20 Dn20 4040-4 4138 4018 Dn20 Dn20 8040-1 1281 1093 Dn40 Dn25 8040-2 2297 2109 Dn40 Dn25 8040-3 3313 3125 Dn40 Dn25 8040-4 4329 4141 Dn40 Dn25 8040-5 5345 5157 Dn40 Dn25 8040-6 6361 6173 Dn40 Dn25