One of the screws in the old shelf came loose and disappeared, so I searched online for the same screw. To be honest, I didn't know how to find the same type of screw. I removed another screw in the shelf and took a photo of it so I could search for the same type using Google Search. I also measured the length and width of the screw so I could find the same one. Perhaps it's right, but I don't know if it's the correct one until I put it back in the shelf.