Comparison FX CorDiax 60 in Relation to the FX 60-Dialyzer

Inclusion Criteria: * Patients who are treated by post dilution on-line HDF for at least three months. * Patients who reached a dialysis dose (Kt/V) of at least 1.2 at the last two monthly checks, * Patients who are on a stable anticoagulation and anemia management, * Patients who are clinically stable outlined by the medical history of the patient, based on judgment of principal investigator, * Patients who are on a regular thrice weekly HDF schedule, * Patients who have a good vascular access (fistula or graft) which enables easy insertion of the needles and suitable effective blood flow (\> 300 ml/min), * Patients who are able to understand the nature and requirements of the clinical investigation and have given written informed consent, * Patients who are aged 18 years or older. Exclusion Criteria: * Patients who do not meet the inclusion criteria, * Patients with active HBV, HCV, HIV infection, * Patients who are severely malnourished patients as judged by the principal investigator, * Patients who are known or suspected to have allergy to the trial products or related products, * Patients who are abusing non-legal drugs or alcohol (defined as an average daily intake of more than one liter of beer per day or an equivalent amount of alcohol in other beverages), * Patients who have been diagnosed a current active malignant disease, * Patients who participate simultaneously in another clinical investigation or in other clinical investigations during the last month, * Patients who are uncooperative.