The Datum 8040 Rubidium Frequency Standard is a high performance 10MHz frequency standard in a 1U high, 19 inch rack mount plug and play package. Based on many years of refinement, the Datum 8040 rubidium physics package is a design that offers high reliability supported by tens of thousands of fielded units. The standard instrument offers power supply selection to meet a variety of needs. A wide range of available individual options coupled to the highly stable rubidium physics package's known performance level permit tailored configuration to address specific application needs.