Canon EF70-200mm f/2.8L IS USM
Here is the description and specs from the Canon Website:
"Incorporating Canon’s second generation Image Stabilization technology, this telephoto zoom responds in as little as 0.5 seconds, while providing up to three stops of correction for camera shake. Its AF system has been refined for better response time and tracking speed. And even the new 8-blade circular aperture offers a more pleasing out-of-focus image. Constructed to pro standards, this fast zoom is also highly resistant to dust and moisture, too.
"Main Unit Spec:
Focal Length & Maximum Aperture: 70-200mm 1:2.8
Lens Construction: 23 elements in 18 groups
Diagonal Angle of View: 34° - 12°
Focus Adjustment: Inner focusing system with USM
Closest Focusing Distance: 1.3m / 4.3 ft.
Zoom System Rotating Type
Filter Size: 77mm
Max. Diameter x Length, Weight: 3.4" x 7.8", 3.24 lbs. / 86.2mm x 197mm, 1470g"