The prime Sigma f/2.8 EX DG APO HSM is 8.3 inches long without the lens hood, and weighs in at 5.3 pounds. It has 11 elements in nine groups and a drop-in 46mm filter. There are nine diaphragm blades here as well. Like the zoom, it's available in Canon AF, Nikon AF, and Sigma AF mounts, and adds both Pentax AF and Sony/Minolta AF versions, as well -- though these don't have hypersonic motors, so the HSM is missing from the naming of these two versions. They sell for about $2,600, with the Sigma AF version again being a few hundred less.