QNAP TS-453U-RP-US Diskless System Powerful, reliable and scalable NAS for SMBs Port RJ-45: 4 RJ45 Gigabit Ethernet ports Port USB: 5 USB 3.0 (front: 1, rear: 4) HDD Interface: 4 x 3.5 or 2.5 SATA 6Gb/s, SATA 3Gb/s hard drive or SSD Form Factor: 1U, rack mountable Processor: Quad-core Intel Celeron 2.0GHz (up to 2.41GHz) Default/ Max. Memory: 4GB DDR3L SDRAM NOTE: 1.The system memory can be increased to 16GB by installing three additional 4GB Long-DIMM RAM module. 2.For the information of RAM module installation and compatible NAS models, please refer to the QNAP RAM Module Installation Guide LEDs: Status, LAN, USB, HDD 1, HDD 2, HDD3, HDD4 Power: Power consumption (W) HDD standby: 23.54W In operation: 39.86W (with 4 x 2TB HDD installed) Power supply Input: 100-240V AC, 50/60Hz; Output: Redundant 250W