Lowrancee
That's why I bought Lowrance, and Eagle. Same chips for all their hand held and mounted chart plotters/GPS units. One chip, $99.00 has all the NOAA charts on it. And fits all my units. Love the H2Oc hand held. Has a color screen, and ties into my DCS on my VHF and my auto pilot. Love my black and white Eagle, 5" screen, works great, have that one on my power boat, and a 7" Lowrance color chart plotter on my Bristol 30.