Canon EF-S 55-250mm f/4-5.6 IS 2.2x High Definition Super Telephoto Lens (This Lens Mounts On Top Of The Canon EF-S 55-250mm f/4-5.6 IS lens) 2.2x High Definition Telephoto Lens designed to mount atop traditional SLR lenses. Optimized For Mega Pixel Photography. High Definition Digital Lens (3 Groups/3 Elements). MultiCoated Optical Glass Uses 72mm Filters. Extreme Speed Auto Focus yields crisp and clear images.