The new Venus Optics Laowa 25mm f/2.8 2.5-5X Ultra Macro lens for Nikon F-mount is available for pre-order at the official Laowa website and at B&H (pre-orders from the website usually ship faster). The official release is expected at the end of the month.
Additional information on the Venus Optics Laowa 25mm f/2.8 2.5-5X Ultra Macro lens including sample photos, technical specifications, MTF charts and more can be found at PhotoRumors.com: