Hi, Yes, I have them on our Mainship 390 . They were OEM on the water tanks, but had no level gauge on the holding tank, so I called them, & they made me up a new panel , which also showed the waste tank, the new PC board & the foil tape that goes up the side of the tank (about 2" wide) from top to bottom.. I installed mine without looking, by just sliding my hand up one of the tank sides....easy. To calibrate, just fill the tank(s), adjust the PC board & empty... Works fine.............Ken, Tampa