These are tdcgsav.png files. You use them with the game 3D Custom Girl. (For first time users: Put these in My DocumentsTechArts3DTDCG, and load them up ingame.)
If you don't know what 3D Custom Girl is, please google it. Hongfire has good resources on this game.
If these doesn't work please drop me a message.
(Note: You need the latest version of 3DCG [XPr4 I think])