This is a set of 16 low-profile flat-head screws for securing 2.5-inch HDDs and SSDs to NAS HDD trays. These are unused, as they were included in a maintenance kit I purchased for a new Synology NAS but were not needed. I have multiple sets available, so if you would like more than 9, please let me know in the comments. I can offer a slight discount on shipping. These screws are for fixing HDDs to NAS HDD trays from brands like QNAP, Synology, I-O DATA, ASUSTOR, and METIS PLUS. Regular flat-head screws may have heads that protrude and prevent the tray from fitting into the NAS enclosure. However, these screws fit neatly into the screw holes, allowing the tray to slide in and out smoothly without interference. Perfect if you need screws when switching from an HDD to an SSD!