It has an internal oscillator that allows time measurement.
Comes with push buttons
Counter input voltage: 3~12V DC
Power supply: 9-12V DC
Velleman Multi-function Up/Down Counter Soldering Kit counts inputs via onboard push buttons or external pulses.
The memory function constantly compares the current value to the preset value and activates the output whenever the two are equal. The kit comes with a simple circuit board and wire connector (20cm wire).