The Sigma Telephoto f/4.5-5.6 Zoom Lens has 135 mm to 400 mm focal length. This APO series lens features auto and manual focus and is designed to be used with 35 mm SLR, digital SLR bodies. It has a 3.5-inch diameter and weighs 1200 grams. Additionally, this Sigma lens features LD glass, aspherical lens and rear focusing system for added functionality.