Mark II. Mark I is also available (you can find it on my profile).
In the upgraded version of the 24-70, Sony made it lighter, smaller, improved minimal focusing distance, and added an optional manual aperture ring. The lens hood has an opening to adjust/twist CPL and VND filters.
This lens is ideal for gimbal work. It also has improved IQ (resolution power), microcontrast, and autofocus performance over the already-great Mk. I.