There are two available grisms in the reimaged/spectrograph mode: 300 l/mm and 600 l/mm. There is no available tilt for the grisms, so the wavelength coverage for the standard longslits is fixed. See Table 6 for a description of the grisms.
It is possible to obtain a different center wavelength by constructing a longslit (or multislit) mask that is offset in the focal plane along the dispersion direction. See the section on making multislit masks for a description of how to do this.
Interference filters are best placed in a parallel beam, so that their appropriate place in this instrument is in the grism wheel. Judy Cohen has a filter holder for the grism wheel; see her to use it. The clearance at the top of the filter holder is small, so it requires shaving off the top of the screws.