Cokin H3H3-21 Expert Kit incl. filter holder, 4 rings ( P452, P455, P458, P462), 3 filters (P121, P121M, P153)The COKIN Expert Kit is an excellent introduction to working with Cokin filters. Because the Expert Kit contains everything that photographers and filmmakers need for working with gray filters. Allow the area to be darkened to be set simply but precisely where the photographer wishes or the composition requires it. There are no limits to creativity. The Cokin Filterkit can also be used for other applications. The Expert Kit from Cokin contains a filter holder and four adapter rings as well as three different filters: the ND4 gray filter (N° 153) reduces the incident light by two apertures. The GND8 gradient filter (N° 121) partially reduces the incidence of light by 3 f-stops while the GND4 filter (N° 121M) provides a gradient darkening of 2 f-stops.