Runleader electronic tachometer.

Digital tachometer: up to 25,000 rpm.
Engine speed resolution: 10 rpm.
Display of the partial time and total time.
Reset of the partial time.
Display of the maximum speed reached.
Adjustable for 2 or 4 stroke, from 1 to 12 cylinders, 1 pulse for 1 engine revolution, 1 pulse for 2 revolutions or 2 pulses for 1 revolution.
Power supply by winding around the wire of the spark plug.
Lithium battery CR2032.
Cable length: 1 m 50.
Dimensions: 3.5 x 6.8 x 1.7 cm.