the universal type( measure and trim rod) I have used last for awhile ,but the wiper arm wears out to me to quickly. so you get erratic readings. I am trying out a non-trim arm type it uses a float that goes straight up and down on a post ,the only thing with them is ordering the matching length to depth of the tank,there is no adjusting. I have not placed it in the tank yet, but it seems to work well enough as I have tested it before I install it.