They are very sensitive 1/64th or less of a turn to only one adjustment screw makes a very large oil level difference from one tube to the other making exact balancing almost a breeze. Mine came to the exact same level on each side but you have to allow any changes to the settings to settle down. Very small adjustments make a big difference. Just rough tuned right line was 7 inches away from the left tube each movement can be seen almost instantly as you get close then slow down and let each tiny movement settle till both levels are the same. I've used mercury gauges in the past and this is a lot more sensitive and cannot harm you, the environment, or the engine if a line comes off and sucks your oil into the engine no real harm just a small amount of smoke. Don't want to burn mercury in your engine, very bad thing..