  Binary properties are an important diagnostic of the star and brown dwarf
formation processes. While wide binaries appear to be rare in the sub-stellar
regime, recent observations have revealed Ophiuchus 162225-240515 (2MASS
J16222521-2405139) as a likely young ultra-low-mass binary with an apparent
separation of ~240 AU. Here, we present low-resolution near-infrared spectra of
the pair from NTT/SOFI (R~600) and VLT/ISAAC (R~1400), covering the 1.0-2.5um
spectral region. By comparing to model atmospheres from Chabrier & Baraffe and
Burrows et al., we confirm the surface temperatures to be T_A = (2350+/-150) K
and T_B = (2100+/-100) K for the two components of the binary, consistent with
earlier estimates from optical spectra. Using gravity sensitive K I features,
we find the surface gravity to be significantly lower than field dwarfs of the
same spectral type, providing the best evidence so far that these objects are
indeed young. However, we find that models are not sufficiently reliable to
infer accurate ages/masses from surface gravity. Instead, we derive masses of
M_A = 13 (+8/-4) M_J and M_B = 10 (+5/-4) M_J for the two objects using the
well-constrained temperatures and assuming an age of 1-10 Myr, consistent with
the full range of ages reported for the Oph region.
