AP Racing is a UK based company.
https://www.apracing.com/aboutus.aspx
In the US, AP Racing BBK products are distributed by Stillen.
http://apradical.stillen.com
AP Racing won a patent case earlier this year.
https://www.apracing.com/blog/post.aspx?Page=189
Great discussion on AP Racing caliper design:
http://apradical.stillen.com/brake-t...brake-calipers