You are buying a serial flash memory chip programmed with your binary - UEFI/BIOS image, etc.

Winbond 25Q64FWSIQ 64Mbit serial flash memory
1.8V operating voltage
Capacity 8388608 bytes

1. You provide us the binary file 8388608 bytes long.
   
2. We program that binary file to the chip.
3. We send the chip to You