Thermo Fisher Scientific has developed an innovative series of test adapters based on high purity natural Lutetium-Oxide (containing the isotope Lu-176 with a 28 times greater half-life then K-40) to provide all users with the capability to "challenge" their radiations detectors functionality. Theses adapters can be used for performance verification of highly sensitive gamma detectors and pancake type beta contamination probes. Unlike other materials and objects containing natural radioactivity - such as old watches or incandescent lantern mantles - these test adapters have an activity that is well-defined and reproducible. Due to their natural origin and low specific activity, under US DOT or IATA rules for dangerous goods shipments these adapters are not considered as radioactive material.