When sourcing dialyzers, the most critical technical factor is the membrane material, typically Polyethersulfone (PES) or Polysulfone (PSU), known for excellent biocompatibility. You must evaluate the Effective Surface Area (ranging from 1.0 to 2.2 m²), which determines the clearance efficiency. Additionally, distinguish between High-Flux and Low-Flux membranes based on their Ultrafiltration Coefficient (Kuf); high-flux dialyzers are essential for removing larger middle-molecule toxins like β2-microglobulin.