Sigma 18-200mm f/3.5-6.3 DC Lens for Pentax and Samsung Digital SLR Camera

The lens design incorporates an inner focusing system%2C which prevents the front of the lens from rotating%2C making it particularly suitable for using circular polarizing filters and petal shaped lens hoods%2E The overall length of the lens does not change during focusing%2C ensuring convenient handling and ease of use%2E A zoom lock switch eliminates %91zoom creep%92 during transportation%2C a convenient addition when traveling%2E