here is what to do
google "model racing technology" (their full name)
which gives this page
https://www.google.co.uk/search?q=mo...EYHI0wWSv4CwDQ
then the second one down shows its a pdf form for the ptx..... simples
or on this page use the search box and there are full instructions of how to order one, I think the thread title is mrt rc4?