Raynox HDP-2800 ES - High Definition Diagonal Fisheye conversion Lens 0.28x.
The HDP-2800ES lens is a conversion lens for capturing an ultra wide angle image in using with the High Definition Digital camcorder. The lens is particularly designed to be in focus through the whole zoom range of up to 5x.
The lens is made of the high index optical glass elements in 3-group/3-element formula, and it's made in compact size and light weight. It achieved an amazing high resolution power of 475 lines/mm at center (MTF30%). Mounting on the wide angle lens of f=26mm or less (35mm film equivalent) focal length, it will be possible to shoot the scene of 180-degree diagonal.

The two adapter rings of 37mm and 43mm come with the lens in the original factory package for use with the same filter sized lenses.