Fotodiox Pro 6.6"x8.5" Grad 2-Color Twilight Effect Filter (Blue / Pink / Clear) - for WonderPana 66 & FreeArc Filter Systems Premium grade, super thick, optical polycarbonate (CR39) gradient filter This filter is graduated from darkish blue at the top to a pink horizon to clear bottom Provides a cool image ideally suited to creating a late afternoon/early evening twilight effect Most commonly used on skylines for landscape work. 24 Month Manufacturer Warranty