Our apologies for not communicating this better, but the sieves for the Ball Sorter activity (NanoDays 2012) will be shipped in the same box as the nano gold. The sieves did not arrive at the warehouse in time to pack them in the large box. So, in an effort to avoid sending all of you yet another separate box, we did some troubleshooting and decided to pack them with the gold.
To recap - the kit will still come to you in 3 shipments: the large, main box; the puzzle blocks box; and the small box containing nano gold and the sieves. The small boxes should be shipped out by January 20th.
Thank you for your patience and, again, our apologies for any confusion!