This lens was launched in 2009 alongside the 7D camera, with which it's often bundled as a "kit" lens.  That "kit lens" designation is often something to be a bit wary of, but not in this case - the 15-85 is one of the best of the breed.  Canon have fitted it with their fast and silent USM focussing; the excellent IS system is worth 4 stops of exposure; and overall image quality is very good - nearly the equal of the excellent EF-S 17-55mm f/2.8 IS USM. It's a great all-in-one lens which can live on your camera.

COMPATIBILITY NOTE: This lens only fits the following EF-S mount cameras: 7D, 20/30/40/50D, 300/350/400/450/500/550D, 1000D. It does not fit on 1D or 5D series cameras.