Thecus 1U4500 Passes IEC / ISO Certified Reliability Test The CE marking is a mandatory European marking for NAS products to indicate conformity with the essential health and safety requirements set out in European Directives. Thecus products are evaluated by a Taiwan Accreditation Foundation (TAF) certified independent test laboratory. CE Verifications of Compliance are issued in order to apply CE marking on Thecus products. Those verifications are to document that Thecus products meet the relevant requirements,