10t 48p (or .5 modules i think) 3.2mm or '1/8' shaft....
i use these on my lehner motor on my trex helicopter... also used on Ikarus ECO8 heli...
see this site:
http://www.hobby-lobby.com/ecoparts.htm
"IK67108 PINION 10T 3.2mm $ 4.90
IN STOCK"
not to rain on the 44 of them pararde from RRP... RRP may very well make a better quality one, i don't know?
the first one i used seemed to wear out more quickly on the heli. and began to wear the plastic main gear mesh a bit as well too, but i think the 1st 10t i had came with the Lehner motor from overseas...
just that they're not worth much more than $8 i don't think. $7.90 shipped ANYWHERE in the world.
never had any probs with the threads in the base, very solid i thought. use a dabble of locktite (not the impossible stuff, just medium hold).