This is for sofas with separate back and seat cushions. Set of 4 pieces: 2 back covers and 2 seat covers. After replacing the sofa, I washed these and stored them in the closet, thinking I might use them again someday. However, I don't think I will, so I'm putting them up for sale. I only used the seat covers at my house. I didn't use the back covers, but the elastic on one of them seems to have deteriorated, and it's stretched a bit. The size is L. I measured them flat without stretching them. Please check the images for details. Images 1 and 12 are examples of how they look when installed. The back covers have the opening at the bottom. They have been cleaned at home. Please refrain from purchasing if you are looking for a perfect product like those in stores, as these are items stored at home. Please refrain from purchasing if you are concerned about minor details. They will be compressed for packaging, so please be aware of creases. We look forward to your purchase if you understand the above.