A successful beryllium reflector applicable to land-, sea-, air- and spaceborne surveillance systems is the culmination of a joint effort between the Customer and the Manufacturer. It involves interfacing contributions from Engineers in a number of disciplines such as systems, optics, stress analysis and, most importantly, machining. It requires the knowledge of the characteristics and the experience in the special handling technology of beryllium. It demands that the Manufacturer has an appreciation of the End-User's system requirements and that the Customer has an awareness of the Producer's expertise and potential in order to achieve a feasible production design specification of a metal optic. The average mirror density within the envelope of a mass relieved beryllium optic is about 0.6 g - cm-3. The essential steps from concept through design analysis and manufacture of a typical stiff, beryllium, low inertia, lightweight 1 kilogram (2.2 lb), active plane mirror 35.6 cm X 21.6 cm X 2.7 cm (14" X 81/2" X 11/16"), are presented.