This is: a set of 4 cacheted, unaddressed FDCs from Vatican City of the 8 stamps issued on March 6, 2008 to commemorate 500 years of the Sistine Chapel. There are 8 stamps on 4 covers, 2 to a cover.
These 4 covers, cacheted by Geocover, feature renderings of the paintings on the walls and ceilings of the Chapel. This issue has high values in it, including 2-euro and 5-euro stamps.
See the scans for details.