The spectral resolution of the instrument at different wavelengths has been estimated by measuring the FWHM of the ARC-lamp emission lines at different wavelengths (and orders), along the dispersion axis. The average spectral resolution is R~63000+-4000, ranging from ~60000 at the blue end (~3900 AA) to ~70000 at the red end (~9600 AA). There is a clear wavelength dependency of this resolution, as can be seeing in the Figure.