3.5-inch RK3399K SBC breaks out with mini-PCIe and dual M.2 - LinuxGizmos.com
Kontron’s 3.5”-SBC-R39 board provides a 2.0GHz, hexa-core RK3399K with up to 4GB soldered LPDDR4, up to 32GB eMMC, 2x GbE, 5x USB, DP, HDMI 2.0, mini-PCIe, and M.2 B- and E-key slots.
Rockchip's RK3399 has been seen on several Pico-ITX boards...