It's the plug half of the Micro-Fit 3.0 interconnect system — the side that terminates the wire harness and locks into the receptacle on the PCB. This plug accepts the standard Micro-Fit 3.0 crimp terminals (43030 series for 20-24 AWG, 43031 for 18-24 AWG) and mates with the 43025 series vertical or right-angle receptacle headers. The panel-mount ears let you fix the plug to a chassis or bulkhead, taking the cable strain off the PCB header.
The mating connector for the 43020-1008 is any 43025-series Micro-Fit 3.0 receptacle header with 10 circuits — vertical or right-angle, through-hole or surface-mount. The 43025-1000 (vertical) and 43025-1800 (right-angle) are the direct mates. For the crimp terminals, use Molex 43030-0001 (20-24 AWG) or 43031-0001 (18-24 AWG); both are gold-plated and rated for the full 5 A per circuit of the Micro-Fit 3.0 system. The panel-mount feature on this plug requires a rectangular cutout per the Micro-Fit 3.0 application spec.