This product is either discontinued or we cannot get that from suppliers.
QNAP TS-431P2-4G 4 Bay Diskless NAS, Annapurna Labs AL-314 Quad Core 1.7GHz, 4GB DDR3 (1x 4GB) RAM (1x SODIMM, Max. 8GB), 4x SATA 6Gb/s, 3Gb/s HDD or SSD, Hot-swappable, 2x GbE RJ45 LAN Ports, 3x USB 3.0 Port (1x Front, 2x Rear), 512MB NAND Flash.
The TS-431P2 features three USB 3.0 ports and dual Gigabit LAN ports, delivering outstanding multitasking performance for your backup, synchronization, and remote access needs on a secure private cloud.