Case for Atomic Oscillator Clock, Model FRK, by Efratom GmbH, Munich, as used to baseline the key concepts and hardware for the Global Positioning System (GPS) 1971-1974, and presented complete with gold cover to Hugo Fruehauf, the Chief Engineer for the GPS system, upon his departure from Efratom in 1996. Case for Atomic Oscillator Clock 1960-1996
