This product is either discontinued or we cannot get that from suppliers.
ASRock H310CM-HDV/M.2 LGA 1151 M-ATX Motherboard, LGA 1151 Socket (Supports 8/9th Gen Intel CPUs), Intel H310 Chipset, 2x DIMM Slots (Supports DDR4 2666), 1x Gigabit LAN 10/100/1000 Mb/s, FF Micro ATX (22.6 cm x 18.8 cm), 1x PCIe 3.0 x16, 1x PCIe 2.0 x1, 4x SATA III 6Gb/s & 1x M.2 Slot, 4x USB 3.1 Gen 1 (2 Front, 2 Rear), Graphics Output Options HDMI, DVI-D, D-Sub, 7.1 CH HD Audio (Realtek ALC887 Audio Codec), ELNA Audio Caps.
The PCIe Gen2 x4 interface pushes data transfer speeds up to 20Gb/s. In addition, it also supports SATA 3 6Gb/s M.2 modules, and is compatible with ASRock’s U.2 Kit for installing some U.2 SSDs.