This product is either discontinued or we cannot get that from suppliers.
Qnap HDD Tray Of ES Nas Series SP-ES-TRAY-WOLOCK, NAS Accessories, Drive Mount Kit, Hard Disk Drive.
HDD Tray of ES NAS series, with black flat head machine screw x4 for 2.5" HDD & silver flat head machine screw x4 for 3.5" HDD.