Any panel made from monocrystalline or polycrystalline. Stay away from any solar panel that is described as amorphous. Although they are priced much lower than monocrystalline panels, they are only 6%–9% efficient. Monocrystalline panels will usually have a blue color and when looking at the panel, you will be able to make out individual cells (usually square, hex or octagon shaped). Amorphous solar panels will be brown / tan and and will look like all one cell with straight lines running from end to end.
Because most RV roofs are rubber. We do not recommend any panel that is glued to the roof.