Mass-radius diagram for binary components of J093010, compared with Dartmouth model isochrones for solar metallicity (dotted lines, corresponding to 1, 8, 9, 10 and 14 Gyr from bottom to top), and with empirical masses and radii for collected detached (red diamonds) and contact (blue triangles) eclipsing binary components. The binary components of J093010A are indicated by larger bold-face red diamonds, and those of J093010B by larger bold-face blue triangles.