ZTC 64GB Armor 42mm M.2 NGFF 6G SSD Solid State Drive. Model ZTC-SM201-064G 64GB ZTC Armor Solid State Disk SATA 6Gbps Ultra-compact SSD, currently the smallest in the market Read speed up to 550MB/sec - write speed up to 490MB/sec Prefect SSD upgrade for ultra-small devices like HP Stream 200-010 Mini Desktop or the Acer C720 Chromebook M.2 NGFF 42mm form factor. Based on Toggle 2.0 MLC NAND Flash