Digital cylinder leak test: This test instrument can be used for cylinder leak test for automotive engines. Helps to quickly locate cylinder leak problems and provide more accurate fault diagnosis than a compression test would. Includes the three main spark plug thread adapters M18 / M12 / M10 Digital multimeter function: This test instrument has a digital multimeter function, which can accurately measure various electrical parameters such as voltage, current, resistance, frequency, etc., It has the capacity to be used on AC & DC voltage & includes automatic range function.