You can search on Google eBay amazon.you can ask seller

http://youtu.be/r3D2kF9EA0Y

try this. If u still can't reach them, write xpert si-4431 on youtube bar. Watch the video uploader named "muratordu61". You can see a difference of servo speed between those 2 videos. Because, on truggy servo supplied by rx8 esc's 5amp rated bec, on buggy it is suppied by hw sct pro esc's 3amps bec.

I seen the servo,it is 9g mini 6v 2.8kg servo,it can apply for car model,plane model,heli model , robot and fixed and wing.