The lightweight QDA-UMP4A allows you to install an M.2 PCIe NVMe SSD in a 2.5-inch U.2 (SFF-8639) PCIe NVMe SSD slot of a QNAP NAS. (M.2 SSD sold separately) No drivers required No extra software or drivers are needed to use the QDA-UMP4A. Budget-friendly, wider choice Compared to U.2 SSDs, there is a greater selection of M.2 2280/2260/2242/2230 NVMe SSDs on the market. You can find a drive that fits your budget and requirements. Gear up with flagship all-flash NAS Supercharge your data-intensive applications with QNAP's U.2 SSD based all-flash NAS models in a cost-effective way. M.2 SSDs installed in a QDA-UMP4A are hot-swappable, allowing you to easily replace drives and reduce potential system downtime. Thermal pad and heatsink included M.2 SSDs may overheat and suffer decreased performance during prolonged high-speed operations. The QDA-UMP4A includes a thermal pad and heatsink to ensure stable performance.