QNAP TS-431K Cloud Storage: CPU - AnnapurnaLabs, an Amazon company Alpine AL214, 4-core, 1.7GHz, 32-bit ARM/ System Maximum Memory - 1GB DDR3/ Flash Memory - 512 MB (Dual boot OS protection)/ Drive Bay - 4x 3.5-inch SATA 6Gb/s, 3Gb/s/ Drive Compatibility - 3.5-inch bays; 3.5-inch SATA hard disk drives; 2.5-inch SATA hard disk drives; 2.5-inch SATA solid state drives/ USB port - 2x USB 3.2 Gen1/ Form Factor - Tower/ LED Indicators - Power, Status, LAN, USB, HDD1-4/ Buttons - Power, Reset, USB Auto Copy/ Operating temperature - 0 - 40 °C (32°F - 104°F)/ Storage Temperature - -20 - 70°C (-4°F - 158°F)/ Relative Humidity - 5-95% RH non-condensing, wet bulb: 27˚C (80.6˚F)/ Power Supply Unit - 90W Adapter, 100-240V/ Fan - 1x 120mm, 12VDC/ System Warning - Buzzer