The 35953 Adapter enables connecting a M.2 PCIe SSD and a M.2 S-ATA SSD (42/ 60/ 80mm) additionally. One M.2 SSD is connected by PCIe X4 interface, which enables a super-fast data transfer of 32Gbit/s. The other M.2 SSD is connected by S-ATA data cable and enables a transfer rate of up to 6Gbit/s. Just fix the SSDs on the adapter and mount it in a free slot.