The SLR Hut Sigma 24-105mm f/4 DG OS HSM Lens is a wide-angle to medium telephoto zoom lens with constant f/4 aperture. Designed for both full-frame and crop sensor Canon DSLR cameras. The lens integrates three aspherical elements into its construction, as well as two SLD and two FLD glass elements to help minimize aberration, field curvature, and distortions throughout entire zoom range. Super multi-layer coating has also reduces surface reflection, lens flare, and ghosting to produce high quality contrast and color fidelity results.