What are these?

[Kikaida]

Found these on a hike in Kaua'i late last month while hiking on some private property (permitted). This was being taken care of by someone. We were told not to pick anything we found so we left it alone (so tempted). Aside from the color, the skins were smooth as a plum and not lemon-like in any way. No pits or wax. Just what looked like a paper thin, paper smooth, flat yellow-orange.