The PM 6669 is an economic, easy-to-use counter that meets your most stringent demands for high-precision measurements, reliability and durability.
The multi-function PM 6669 offers frequency, period, count totalization, ratios, pulsewidth and frequency difference measurements.

SPECIFICATIONS:
• Measuring Modes: Freq. A Freq. B Period A RPM A Totalize A. Freq. A/Ao Freq. A-Ao Pulse Width A.
• Frequency Range: Freq. A: 10 Hz to 120 MHz (1 Mohm) / Freq. B: 100 MHz to 1.1 GHz (50 ohm)

PM6669/431 OPTIONS:
PM9607 MTCXO Oscillator
PM9608 1.1 GHz HF-RF Input
115/230V 44-440 Hz

NOTE: Ours are the brown Philips counters, as pictured.  They have paint chips, but work great.