Buzz Feiten Sattel:

http://www.buzzfeiten.com/Become_a_Retrofitter/become_a_retrofitter.html

Earvana  Sattel:

http://www.earvana.com/how.html

Fender Intonation:

http://www.fender.de/service_und_info/service/intonation.html

Stephen Delft    Sägezahnsattel

http://www.mimf.com/nutcomp/