These are leftover prototype PCBs.  These won't be re-stocked.

Features

• Ultra Low Profile - Only 7mm tall with switches!
• 40 key ortholinear layout. 10 column, 4 row.
• Wireless Ready - On/Off switch and battery pads. ZMK firmware.
  
• Open Source.

Listing is for PCB only.  Switches/Keycaps can be found from MKUltra or on AliExpress.

Firmware

QMK / ZMK