PINE64 has started selling the PinePhone Pro Explorer Edition, another Linux-based smartphone produced by the company. The Explorer Edition costs US$399 and comes with a Rockchip RK3399S, a 720p display and a 3,000 mAh battery, among other features.
https://www.notebookcheck.net/PinePhone-Pro-Explorer-Edition-Linux-based-smartphone-launches-for-US-399-with-the-Rockchip-RK3399S.592584.0.html