Infrared spectra at 1.9-2.5 μm and narrowband photometry of three low-mass objects, DENIS-P J0205.4-1159, J1058.7-1548, and J1228.2-1547, are presented. As shown previously by Delfosse et al., DENIS-P J0205.4-1159 shows an absorption feature at 2.2 mum. We attribute this absorption to H_2. A simple two-parameter analysis of the K-band spectrum of low-mass objects is presented in which the relative strength of the H_2O and H_2 absorption bands is found to be correlated with the effective temperature of the objects. The analysis confirms that DENIS-P J0205.4-1159 is the lowest temperature object of the three. We present narrowband photometry of these objects that provides the continuum flux level in between the deep H_2O absorption bands. These data show the continuum level accurately for the first time, and they will provide tight constraints for spectral models of these interesting objects.