Lens Type: Wide-angle zoom lens
Mount: EF-mount (compatible with Canon full-frame and APS-C DSLR cameras)
Focal Length: 17-40mm
Aperture: Maximum aperture of f/4
Autofocus: Ultrasonic Motor (USM) for fast and silent autofocus
Minimum Focus Distance: 0.28m (0.92 ft)
Construction: 12 elements in 9 groups, including one Super UD lens and two aspherical elements
Filter Size: 77mm
Dimensions: 83.5 x 96.8mm (3.29 x 3.81 inches)
Weight: 475g
