This is a mains powered Black Star Apollo 100MHz Universal Counter Timer.  This Frequency Meter / Counter has a 8 digit red LED display and has a fairly versatile specification.  I use it as a spare bench Frequency Counter.

 

BNC Input A: DC to 100MHz.
BNC Input B: DC to 2MHz.
BNC Internal/External Reference Oscillator.
Function: Time Interval, Period, Stop Watch, Count, Ratio, Frequency, RPM.
Gate: Ratio 1, 10, 100, 1000; Frequency 10mS, 100mS, 1S, 10S; RPM 60mS, 600mS, 6S, 60S.
Range: 10kHz, 100kHz, 10MHz, 100MHz, PSC, Lock.
Single Measure
Start/Stop
Reset
Hold
Hold Off.
Trigger Level, Slope +ve or –ve.
Attenuation x1 or x10
Coupling AC, 50 ohm, DC or LPF.