This product is either discontinued or we cannot get that from suppliers.
Synology DS420+ Seagate 4TB IWN, 4 X Seagate 4tb Ironwolf Hard Drive, Bundle Includes 1 x Synology DS420+ and 4 x Seagate ST4000VN008 Harddrives.
Synology Tax Saver - Ds420+ + 4 X Seagate 4tb Ironwolf Hard Drives (DS420+ Seagate 4TB IWN).