In the last decade a significant amount of observational effort has been made to determine the physical parameters of low mass stars (M < 1 Msol). The most recent observations appear to show a discrepancy between the mass-radius relation predicted by the models and that obtained from the observational data. This discrepancy appear to be explained by assuming the presence of strong magnetic fields in the stars which produce larger radii than models predict. The best source of precise mass and radius measurements are double-lined, detached, eclipsing binaries (DDEBs). By measuring the radial velocities and light curves of these systems, we can derive their stellar masses and radii with accuracies of about 1-2%. However, the number of known low-mass DDEBs is small and for many of the known systems the measured masses and radii have large error bars. In the year 2005 we began an observational campaign to measure the visual and near-IR light-curves for a sample of DDEB candidates with low-mass components and observable from the Northern Hemisphere (delta > -9 deg). The objects of this sample were identified in large scale photometric surveys (NSVS, ASAS, SWASP). For the photometric observations we are using the Carlos Sanchez (JK bands) and the IAC80 (VRI bands) telescopes, both at Observatorio del Teide, Canary Islands, Spain. The IR-band light-curves are less affected by the presence of photospheric spots, which are a common feature in these stars with convective atmospheres and magnetic activity, and can, in principle, provide more precise radius measurements. In this poster we present the complete JK-bands light curves and the models of four of the low-mass DDEB observed in our program: NSVS10441882, NSVS07453183, NSVS10653195, and NSVS02502726.