Phoenix 0.25X Super Fisheye Converter w/49,52,55 & 58mm adptrs. 0.25X magnification makes your standard or wide angle focal length lens an ultra-wide "fisheye" lens Mounts to the filter threads of almost any digital or film SLR lens with series 7 adapter rings 4 adapter rings are included: 49mm, 52mm, 55mm & 58mm With 0.25X: 50mm Lens = 152 degrees; 35mm Lens = 166 degrees; 28mm Lens = 175 degrees angle-of-view Made in Japan with high quality all glass lens construction