Equivalent to a 28-135mm lens, this EF-S lens brings true wide-angle to tele coverage to EOS 20D & Digital Rebel shooters. It has Canons image stabilization system, allowing safe h&-holding at speeds up to three stops slower than otherwise possible. & of course, its optically optimized for digital SLRs. A ring-type USM means both fast & silent AF, as well as full-time manual focus when in the AF mode.