Sigma 18-35mm F/1.8 DC HSM Lens for Canon APS-C DSLR Cameras (Certified Refurbished) This Certified Refurbished product is tested and certified to look and work like new. The refurbishing process includes functionality testing, basic cleaning, inspection, and repackaging. The product ships with all relevant accessories, a minimum 90- 18-35mm focal length, 27-52.5mm equivalent focal length on APS-C cameras F1.8 maximum aperture; F16 minimum Ring-type ultrasonic-type AF motor with full-time manual focusing, 72mm filter size Minimum Focusing Distance 28 cm/ 11.0 in.USB Dock Compatible, MC-11 Compatible.