The Sigma 18-125mm f/3.5-5.6 DC lens is a wide angle to short-medium telephoto for general purpose or walk-around lens use. It is exclusively designed for DSLRs with APS-C sensors and a 6.9x magnification ratio. Sigma 18-125 employs internal focusing to prevent extension during focusing and front elements from rotating. The zoom lock keeps the lens from extending on its own while shooting. The Sigma 18-125mm is a versatile lens with excellent ergonomics and outperforms most kit lenses.