You will get five picture mats cut for 5x7 pictures. They will fit into any 8x10 frames. The opening is cut to 4.5 x 6.5 to overlap a 5x7 picture. The overlap also helps to mount pictures to the back. These mats are acid free and cut from 4 ply mat board. All of our matting is cut from high quality 4 ply acid free mat board. Each mat is precision cut with beveled edges that show off the beautiful white core of the mat board.