Add to Favorite Sellers. SAMSUNG PM991 512GB SSD M. 2 2242 42MM NVME PCIE – BLACK. The item in this listing is an Open Box (packaging maybe slightly distressed). The unit powers on with factory settings restored and includes the original accessories. The unit may have some minor cosmetic marks. Form Factor: M. 2 2242 PCIe NVME SSD. Type: M Key. Dimension: 22mm x 42mm x 2.38mm. Internal Hard Drive.