Did you know that .TK belongs to an small Island country Tokelau? 
Zone Info
.TK is the official country code Top-Level-Domain (ccTLD) of Tokelau.
Zone Use
A .TK Domain is normally used by companies or private entities who are located in Tokelau. In Germany is has become quite favourable as a domain for the Telecommunication (Telekommunikation), or Trekking business.
Characters
Minimum: 4
Maximum: 63
Letters and numbers
Hyphens (“-“), however not at the beginning or directly in front of the TLD
Register .TK domain name as low as €7.50 EUR per year
https://cp.altushost.com/?/checkdomain/domain-names/