This precision ball bearing gearbox is designed to fit the Astro cobalt 05
and 15 motors. The reduction ratio is 31/13 or 2.38 to 1. This ratio allows
the modeller to use an 11 to 12 inch on oldtimer models or scale models and
a 12 inch folding prop on sailplanes. The ball bearings are prelubricated and
need no further lubrication but, the gears do need a little bit.

INCLUDES: One Solid Aluminum Front Plate, twin ball bearings, stainless steel
          spur and pinion, a 1/4" steel output shaft and two socket cap screws.