Spectra/Por Biotech Cellulose Ester(CE) Dialysis Membranes500-1000 MWCO 16 mm An Ultra High Purity and Precise Separation Dialysis Membrane. Vol/Length (ml/cm): 0.81. Dia. (mm): 10. Fourteen precise MWCOs ranging from 100 Daltons to 1 million Daltons.