M2D20: M.2 SSD adapter card with two slots for cache acceleration Synology M2D20 is an M.2 NVMe SSD adapter card designed to increase the input/output performance of NAS devices. The ability to handle multiple NVMe SSD queues greatly aids in latency-sensitive applications such as photo indexing, file searching, and virtualization deployment. HARDWARE In general Host bus interface: PCIe 3.0 x8 Holder height: Low profile and full height Size (height x width x depth): 71.75 mm x 181.9 mm x 15.8 mm Operating temperature: 0 ? C to 40 ? C (32 ? F to 104 ? F) Storage temperature: -20 ? C to 60 ? C (-5 ? F to 140 ? F) Relative humidity: 5% to 95% RH Warranty: 5 years (Notes: The warranty period begins on the date of purchase indicated on the receipt.) Storage Storage interface: PCIe NVMe Supported size: 22110/2280 Type and number of connectors: M-key, 2 slots Compatibility – Supported models (NVMe SSD) SA series: SA3600, SA3400 Series 20: RS820RP +, RS820 + Series 19: DS2419 +, DS1819 + Series 18: RS2818RP +, RS2418RP +, RS2418 +, DS3018xs, DS1618 + More information can be found on the manufacturer website: https://www.synology.com/en-us/products/M2D20