What he means is . . .
If the servo is XXXX make and it has 24 splines on it then you need 24 spline Servo saver
Look on the packet of servo saver before you buy it it will say to fit XXX servo or 24 spline / 26 spline
Also cheap servo's do not return back to neutral ( some times )
Most use HiTec 225mg (mg=Metal Gear and ballraced ) and sell for less than £20 good servo as well
http://www.rc711.com/shop/hitec-hs22...l?currency=SEK