Rubidium frequency standard; output: 10 mhz sine wave, 0.5 vrms; 50 ohms impedance; input power: 22.5 to 32.0 vdc; 18.0 watts max at 25 degrees c ambient and 26 vdc; store at up to 95 pct relative humidity; hardened to ground tactical environment; internal diode protects against reversed polarity; shock (non-op) per mil-std-202e, method 213b, test condition-j; vibration (non-op) per mil-std-202e, method 204c, test condition-a