Both covers contain 2 stamps from the same issue dated May 10, 2008 - "Summer Palace --- Special Stamps". This full set is composed by 6 stamps with the nominal value of 1.20 yuan each. On these above showed covers we have 2 stamps from this issue, entittled "Shiqikong Bridge" and "Garden od Harmonious Pleasures".
Zhou fan invites you to visit his interesting blog: http://www.ejiyou.cn
Thank you, Zhou fan!