This tool is simple to use due to having two gauges with an air regulator and includes a -8 barrel valve injector fitting as well as a hose with a 14mm spark plug fitting on it.
Simply plug the leak down gauge into your air supply turn the gauge on that is preset to a hundred psi and set the leak down on the barrel valve with the other gauge or check cylinder leakage cylinder by cylinder.
Leak down tool has a air ball valve to control air flow and not to shock the gauges when setting as these gauges are precise enough to measure a half of percent to give the racer better repeatability and more accurate readouts.
Leak down gauge is LED readout and has a backlit screen for easy to read numbers. Each gauge uses a nine volt battery and each gauge has a battery life indicator on the gauge read out.
Included with the gauge is a nice foam lined carrying case to protect the tool and each gauge has a rubber protective cover just in case that ah-crap I just dropped my new tool moment happens.
Includes detailed use instructions and batteries are included.