Allows the use of select threaded viewfinder attachments like the DG-2 on all Nikon SLR cameras with a rectangular viewing eyepiece as noted Compatible With Digital SLRs D40, D50, D80, D70, D70s, more→D90, D100, D300S, D3000, D3100, D7000, Film Cameras EM, FG, FG20, N50, N55, N60, N65, N70, N75, N80, N2000, N2020, N4004, N4004s, N5005, N6000, N6006 and Pronea 6i. Not recommended for use with right-angle finders. Physical size, shape and weight of right angle finders make this inadvisable. Use of the DR-6 is recommended.