This is a SIGMA lens that has a 0.18-metre minimum focusing distance and a 70 mm maximum focal length. For those who like to use a filter, this lens has a filter diameter of 82 mm.
From London Camera Exchange
Sigma 24-70mm f/2.8 DG DN Art - For F/L Mount
DigiBroadcast
Sigma 24-70mm F2.8 DG DN Art Lens –L Mount