Depends on the aircraft and the length of the pushrod. 2-56 rod is usually sufficient for up to .60 size planes. Centrally located servos will need an outer tube that is secured in several places to eliminate any flexing of the rod. Short lengths of 2-56 rod are fine without an outer tube. Golden Rods are fine but long lengths sometimes tend to grow a little after sitting in the hot sun for awhile which can throw your trim settings off. I've used Du-Bro Kwik Links and like them. You have to be sure to use the correct size as they are made for 2-56 and 2MM as well as 4-40. If the 2-56 Kwik Links are used on 2MM rod (which is typically supplied with ARF's) they could strip loose.