Difference between product key and activation code - Microsoft Support
: Many sites promising "exclusive" keys bundle them with malicious software. Legal Risks

Tiny Size: One square inch, easy to embed to devices.
OpenWrt: Easy to code; super stable, three years no reboot.
Low Cost: low cost, less than 1watt, unmatched performance.
Interfaces: Hardware support USB, Ethernet, SD, I2C, SPI etc.
OpenSource: Both software and hardware, totally FREE
Long Life: Keep production over 10 years, fast email support.
Difference between product key and activation code - Microsoft Support
: Many sites promising "exclusive" keys bundle them with malicious software. Legal Risks