GMOS-N is one of two identical instruments mounted on the Gemini telescopes.  GMOS-N
is mounted on the Gemini North telescope.

The GMOS are long-slit and multi-slit imaging spectrographs with a 5.5 square
arcminute field of view and a wavelength range of 0.36-1.03 micrometers. An Integral
Field Unit is also available to obtain spectra from a 35 square arcsecond field of
view with a sampling of 0.2 arcsec.
The Nod-and-Shuffle mode, which enables superior sky subtraction, is available with
both GMOS-N and GMOS-S in most spectroscopic modes.