The AT-X 124 PRO DX II offers a smooth and quieter autofocus over its predecessor due to the DC motor and new AF control gear assembly. The lens has also been improved with the introduction of new multi-coating system. The new multi-coating helps reduce reflections that can cause flare and ghosting even more than in the AT-X 124 PRO DX. The AT-X 124 PRO DX II features the one-touch focus clutch mechanism that allows you to switch between auto-focus and manual-focus by simply moving the focus ring forward to the front of the lens or backwards towards the camera. This offers fast and easy manual over-ride in difficult lighting situations. This lens was designed for use with Canon EF-S mounts.