IDAS NB3-PM Nebula Booster OIII and SII 2" Mounted Filter (M48)

IDAS NB3-PM: PM stands for Passband Modification 

Nebula Booster NB3-PM filter for OIII and SII

the NB3, OIII and SII emission lines respectively. The NB3 is a thin-film interference filter having a half-value transmittance band width of about 21nm at the shorter wave length side and about 19nm at the longer wave length side.

ODW stands for Optical DIstance Worker, and is a clear filter to correct the optical distance.

None of the NB2, NB3 or ODW can cut the IR range longer than 750nm, so it is highly recommended you use one of them in combination with an IDAS light pollusion filter or an HEUIB-II filter as the base filter.
You can swap the base filter as well to expand your shooting expressions.