Lens2scope , 7mm wide angle, for Nikon F lenses, black, straight eyepiece 7mm WIDE 1:4 eyepiece for Nikon F mount lens Wide constant 60 degrees apparent field of view with angled observation 17mm eye relief with Pull & Lock eyecup for eyeglass observation Use high refractive index low dispersion Lanthanum glass for optimal optics perfrmance Reinforced detachable tripod mount design ; Fast Release metal lens mount