Canon EF 28-105mm for 3.5-4.5 USM Standard Zoom Lens for Canon SLR Cameras 28-105mm standard zoom lens with f/3.5-4.5 maximum aperture for Canon SLR cameras Ring-type ultra-sonic monitor (USM) provides silent, high-speed autofocusing 1.6-foot close focusing distance; rotating zoom system; 58mm filter size Ideal for Canon EOS A2/Aw3 or ELAN 7 series cameras with built-in flashes Measures 2.8 inches in diameter and 3 inches long; weighs 12.9 ounces